i don't think "smooth skin covering rippled muscles" makes sense.
I know what is implied, but it gives me the impression the skin is moving, not the muscle. The muscle moves underneath the skin. if we can see the muscle moving beneath the skin of these scantily clad dancers, then we assume that a well formed physique is what we are seeing.
Also, most importantly, "rippled" muscle implies that the muscle is in a frozen state and has stopped rippling while the other observations in the sentence are made.
Minuscule is not appropriate either in my opinion, because i don't know how much skin is actually being revealed. So in my edit:
The scantily clad dancers writhed sinuously, muscle rippling beneath their oiled, silky-smooth skin, mesmerizing all who watched.
the provacative dancing is what the audience is paying attention to. If you want to be more precise and read that the audience is focusing on the exposed flesh, you have to be more specific.