If by biamping you mean retaining the passive crossover, it will make zero difference. This is because the voltage available across each section remains the same, so no increase in power. Furthermore, unless the amplifier is unstable and of marginal performance, the superposition principle ensures no benefit.If you can bi amp your speakers then use an amp running in stereo for each speaker. One channel for the highs & the other for the lows.
Increased power and you don't need to bridge.
If by biamping you means removing the passive crossover and using an active crossover, then yes, that can bring many benefits, not least of which is more volts across each section before clipping.
S.