You have to rush down Potemkin, do you actually have any other choice? lol - No use Baiken hanging around because there's nothing she can do to provoke action from Potemkin other than getting in and doing something.
I wouldn't say j.H xx Tatami is a useless tool against him though. Baiken players can still get away with it. Never have I seen matches where she gets busted every time. Maybe because Baiken has a few other options? I dunno. It's alright to use once in a while because it raises the guard meter up a bit...and that's really what you want to do against a character with high stamina.
THE main reason why Baiken loses out in this match is because she simply cannot make any mistakes - PB is like, half your bar. Don't factor that and you'll get squished. :P
If you are using Tatami at mid-max range, then rest asured that you won't get busted. :D