Bi-amping

Only if you use an electronic x-over and bypass the woofer x-over. Simply using a separate wire to the woofer input does nothing because the woofer x-over is still in use. This passive woofer x-over usually has an inductor which compromises amplifier damping. Eliminating the woofer inductor has the benefit of better amplifier control of bass frequencies. And for that an electronic x-over is necessary.

Wire companies that claim to sell bi-wire cables are just pulling your leg! For more profit of course!

There are benefits to Bi-amping in that each amplifier only drives one drive unit (or sets of drive units) and therefore restricts the range of frequencies and dips and peaks in the impedance curve it must drive.