to put it simply, it does.

your using a similar movement for straight muscles, and although real power comes from turning your weight into a punch,having high muscular strength really will help.
muscle strength will aid in core strength allowing you to convert your weight better and faster, but will also add to the "hold of the punch"

when you hit a target, especially with hooks, you need to keep your arm in a solid position and whip it through the target with your body. weaker chest muscles and arm muscles will bend and "give" as you hit the target, and therefore a proportion of the force will be lost.