If you have speakers with bi-wire terminals and two stereo amps you can connect them to the speakers. You have to remove the jumper between the 2 positive and 2 negative terminals of each speaker.
If both amps are the same then you can use one for the left speaker and one for the right. That makes for less crosstalk between channels.
If they are different then you want to use one for bass and one for treble. That way the speakers will sound the same.
If the amps are stereo amps bridged to mono then you would not remove the jumpers and connect the amps as per the owners manual.
This isn't actually bi-amping because there is no crossover before the amps. It has been called vertical amping.