Jose, the consensus of opinion that I've seen suggests that bridging is the least satisfactory of the options (except with regards to comments I've read about Bel Canto Evo amps)because of the graininess that 123hifiman mentioned. Why haven't you tried bi-amping yet? I'm sure you can easily borrow some cables to do it and that would show whether 200 "Meridian amps" per channel are enough for your 802s.

I know that B&W speakers have a reputation for high power requirements but with the current that the M amps provide I'd be surprised if the G57s in vertical bi-amp configuration are not enough. If they aren't, I would check out the monobloc options rather than bridge but you're in an ideal position to try this for yourself. In the end, only your own ears can decide.

Steve

Steve