Why do you think Bi-Wiring improves the sound ?

If it is easy, do it. What can it hurt to find out and know for yourself? If it were a PITA to do, then I would have the same concerns your OP had. But since it would be an easy experiment, do it and report back. You know that further contributions to this thread will continue in the same vein with those advocating one or the other side. (as usual). Have you EVER seen a subject when it comes to our hobby where there is a reliable and absolute consensus? At best these questions are an academic exercise. At worst they are contentious arguments.

I have come to realize that all the opinions, reviews, theories, experiments, discussions in the world do not trump my own experiences. I am the only person who knows what I like and want. And it is EXPENSIVE and time consuming to go through this journey. But your particular situation here is not all that expensive nor time consuming to try. In fact, it could have been done in the time it took this thread to peter out. 

And my reading reviews has done more harm than good for me in the outlay of money department.  I really have not improved the sound of my stereo since 1984, even though I have been through over a hundred components. I have circled back to a very similar system I had back in 1984 much to my satisfaction. If only I had just left it alone. 

A technically good amplifier is like an ideal voltage source with a low output series resistance and able to supply whatever current a load (wire, crossover, drivers) require. The problem is that the long wire presents a series resistance and inductive load with some shunting capacitance which causes the signal at the loudspeaker end to be different from that at the amplifier end, depending on the current being drawn. Even this is a gross simplification. Engineers model elements of a system to be good enough. Enough for what?  Enough for realization of basic function and requirements.  This doesn't mean that a power amp with a DC supply that can deliver 5A at 50V is perfect even though that supply meets its' specifications. In your computer chip, to ensure that a logic gate triggers when expected.  As those systems get smaller and faster, the models have become more and more sophisticated to satisfy basic functional needs.  
Separating the upper and lower sections of the loudspeaker crossover from each other (requires separate terminals) will allow parallel runs from the amp to the speaker. The most basic factor is that, all things being equal two sets of cables will halve the series contribution of the wire to the system signal disturbance. This can also be achieved with a shorter run of wire.
The bi-wire improvement will mostly come about because the high current woofer load distortions will no longer generate a voltage disturbance signal at the tweeter since they will not be present at the high terminals or at the amp terminals (assuming the amp is not a tube type with high output impedence). I could beat this to death but a simple circuit analysis using non-ideal elements will show this. So much for the assertion that there is no science, or more accurately, technical basis. Many people learn basic I=E/R and think they understand everything. A loudspeaker is not a simple 8 ohm resistor, a cable is not equivalent to a small resistance, and I=E/R are not frequency independent.  
Years ago, I used to argue vehemently, as an arrogant, self-assured electrical engineer, that power cords couldn't make a difference because the amp converted (rectified and filtered) AC into DC.  My model must have been too simple since after finally trying different power cords and conditioners my reaction was: "No freaking way!". I've since come to see that the amount of benefit of a power cord depends on the application. I've found the biggest improvements with high power class A amps which are always generating large current pulses, and for relatively noisy components like DACs etc. My preamp was not very sensitive to the power cord since it utilized a sophisticated DC bus followed by a 400 Hz AC system which was then reconverted to DC.

The Vandersteen website discusses this well

Maybe getting higher quality jumpers rather than using the typically crappy factory ones would be a factor too.

Definitely for the high quality jumper vendor. He'd have your money.

I should have asked if bi-cabling or 2 seperate runs of cable sound better ?

Better to whom?
Different? Possibly.

I've since come to see that the amount of benefit of a power cord depends on the application.

What a concept: S Y S T E M    D E P E N D E N C Y
Who'da thought? <vbg>

As oft opined, any specific claim is only valid for the claimant! YMMV

Simple answer on question on if bi-wiring improves or not sound is - yes, it will improve sound.

The longer cable is, the better improvement will be. Alternative to bi-wiring solution to improve sound could be mono-blocks closer to speakers, and shortening cables. If speaker cable is 2ft or less, bi-wiring will not improve anything much.

Main reason to have bi-wiring option is a fact as speaker is not linearly behaving load, and therefore sharing cable connection resistance and inductance will increase intermodulation between low/mid/high. For low freq. speaker resistance of cable should be lower than mid/high, because speakers (almost) never use crossovers with additional in series resistor for lows, and also utilize lowest ESR Inductors $$. Mid/High  crossovers typically have couple of Ohms in series resistors, and therefore 100 mOhm cable resistance does not make any difference. The most important for Mid/High cable is to have lowest as possible inductance.