I've never seem them together in one place, they may be the same person even.
No, if he was I'm pretty sure that the past years Justin has been playing it would have been brought up in almost every match he played. "so Billy, did you know this is Buddy's kid?" And listed in his Bio. And well, just generally known by now.
This is from a 2002 news story
"In the 14-and-under-open division, Justin Hall beat Mike Banks, Jr. in a forced tiebreaker. Banks beat Hall decisively in the first set, 9-3, but lost steam in the second, allowing Hall to win, 9-6. Hall started playing pool with his dad at 8; Banks has been playing in his father’s poolroom since he was 4. Both boys have considered being professional pool players, though Hall also has anesthesiologist on his list of potential careers."