Do you mean Bi-wire or Bi-amp?
Bi-wire meaning from 1 stereo output to 2 speaker inputs?
Bi-amp 2 stereo outputs to 2 speaker inputs.
The reason I ask is that if your AV amp is 7.1 ie an extra 2 rear channels, you are most likely able to bi-amp, ususally via an option on the amp which changes them from rear effects channels to front stereo, or similarly if you have a second stereo front output on the amp (usually front AB) this would also work nicely).
I would argue that Bi-wiring however, is a very subjective topic. I would argue that the extra copper pair of cables add more resistance (especially with 3M plus runs) to the signal and thus colour the sound and would prefer to run a single cable and use quality cable & terminators to link at the binding posts at the speaker end.
/me prepares for a flaming