There's really no "magic number" of watts that will be adequate for a particular speaker. It has more to do with the quality of the amplification (and how honest the amplifier manufacturer is when they tell you the power output) than it does with any particular number.

Some amps just mate better with some speakers. You can do some listening and figure out which one sounds best with yours. Who knows, your favorite might be a low-powered tube amp!

I'm sure there are 100W amplifiers that will sound excellent with your speakers, but quality is more important than quantity.

I have fairly sensitive speakers (92 dB in-room) and a relatively modest amplifier (49W), and I've never felt like the little guy wasn't giving 110%. I live in an apartment, so I also tend to listen at lower levels.

I suspect manufacturers of speakers sometimes suggest minimum watt ratings for amps because a speaker might be more prone to damage because a lower powered amp might be more easily driven into clipping, potentially burning out a speaker coil. I remember reading in a Richard Vandersteen manual that if you have to raise your voice above a normal speaking level, your volume is probably too high. Listen at sensible volumes, and you should be fine.