Jake: I am assuming that since you are asking that you already know that your speakers have the capability to be bi-amped.
The real question is why would you want to add another pair of very expensive amplifiers if, and I hope I am not mistaken about my assumtion, you are not already extremely pleased with the soundstaging and presentation the amplifiers are already providing.
Do you feel your speakers are sufficiently powered? If so, how would you implement the bi-amping? Does your preamplifier have that capability? Would you have to split the signal?
You need to first consider whether your preamplifier can handle the task.
Now, there is always the possibilitie that performance could increase. When one amplifier is only powering mids and highs and another is only powering lows, increased performance is usually experienced. But, before purchasing another ecxpensive pair of amplifiers, do your homework with regards to the actual setup.
Good Luck!