Power is power. Too much is too much. If you fully clip a 100 watt amp then it will send 200 watts to the speaker. IIRC, the RMS rating of a speaker should be the amount of power it can take for 8 hours. Not sure if everyone abides by that though. For short bursts they can take more. For HT, I am not sure if that rating is thermal only or applies to excursion as well. Don't forget that music is dynamic. Even if you actually do send a full signal it won't be for very long at all.

If the speaker is rated right he should be fine.