From Rock Bass range maps I have seen - you are right on the extreme southern end of their present range - so you may be a bit too far south for any large populations of them.
I see you are using surface bugs in trying for them. I learned to fly fish catching Rock Bass in the local river when I was a kid and we always used wet flies - usually with a small spinner ahead of it. The flies that worked best were the "Yellow sally" the "Black Gnat" "Red Ibis"
etc. in size #6 or #8. Never had any luck on surface lures with them. They like a bit deeper hole under some brush right tight along the bank and we also found them in not so deep holes in weed pockets where there was a big rock or boulder they could hide around or under. Sometimes - we would get lucky and find a school of real big ones in a relatively small pool full of bigger rocks and boulders. They will also hang out deep around bridge pilings. But when I wanted a good mess to eat - I used a bobber and worms with a sinker on bottom and fished the brush piles along the bank and fished from the bank.
Hope this helps.