When amending a question to address a point made in an answer or a comment, is it OK to mentioning the answerer name? (e.g., at the end of the question, "To answer Bob's comment: blah blah blah")
It's OK, but it's unnecessary.
If you're adding information to the post that is helpful in answering it (which presumably you are, if you're editing in an answer to a comment), then it doesn't need to be denoted as an answer to a comment. It's just helpful information.
If you're not, it belongs in a comment, where you can reply directly to Bob.
It's not such a massive issue that you should edit it out if you see it in others' posts, but you don't need to do it in your own.