If a user (other than the OP) edits a question and makes it significantly more understandable or better formatted for consumption (reading) is there anyway to reward that user with some rep?
Just karma. It's a good thing to do, but there's no actual rep benefit etc (other than the editor badge).
There have been proposals for voting on edits, but I don't personally see the need, beyond the ability to perhaps flag a particular edit as offensive.
You can go to their profile page, find an answer or question and upvote it.
Keep in mind, I do not advocate this on an arbitrary question. I just think that you'll find if you like the way the person edits, then chances are you will also easily be able to find a very strong answer that they authored all the way through.
The other bonus is that if the question is interesting, you might learn something by reading all the responses on it, and you might end up upvoting a lot of the answers.
The downside is that you might stumble across an answer by that person that you end up downvoting, so they'll be worse off... whoops.
But in general, anyone who is a good editor, will tend to get a lot of upvotes on their questions/answers anyway.