Philojet,
In my experience, bi-wiring is better than a single run of the same wire.
However, I find that a single run of a significantly better wire will sound better and be more bang for your buck than bi-wiring.
So in most cases I would advise upgrading to a better single run wire over bi-wiring with your present wire.
By the way I don't sell Acoustic Zen, but that's damn good stuff.
Duke