Conservatively, yes, but read the manual before you try it. Usually how its done is to set it to bridge, and run the positive lead from the speaker to the left channel's positive output, and the negative lead from the speaker to the right channel's positive output. BTW, The Yamaha Sound Reinforcement Handbook has a great section on amp bridging. This is a book every sound tech should have, and its cheap too (at least at Amazon).
I have been pondering bridging two amps together and if it would work some. My reason for thinking it wouldn't work is that they may be slightly out of phase in which case it would almost be a war inside the speaker as to which amp is driving the speaker more. Anyone have any thoughts on bridging two amps together? Just for the record I don't plan on ever doing it, just thinking of if it would work well or not.