I've noticed some great comments along the way and upvoted them. Will the commenter get any reputation boost from that? (If they do, how many points per vote?) I'm also wondering since I've seen some of my comments get voted up.
No, there is no reputation gained from voting or having received votes on comments.
Comments are a really light-weight mechanism. They are, essentially, meta to a post. A vote on a comment is really just a way of adding credence to a statement; to say that you agree or find the comment interesting without the bulk of adding a bunch of "I agree" or "me, too" or "+1" comments to the mix.
Comments aren't associated with reputation, but there is a badge for leaving highly voted comments.