The voting system - as far as I know - makes no distinction between posts and comments. So if you vote 100% on a comment it gets the same $ as a post you voted 100% on. I admit for minnows that may prevent you from voting on comments not after HF 19 as long as you don't have a slider. We will see and learn.

There was (or is) a discussion about giving comments an own $ pool, but I think that will not happen.