If she's in Pearl's gang, I'm sure Rita and Greg would know each other's faces at the very least. He's a warlock under the same boss as her and they butt heads on occasion, but he tends to be pretty polite towards her followers (if a little anxious). Despite everything, he can appreciate a group of misfits looking after each other, but have you considered putting mufflers on your bikes maybe.

He also volunteers at the Sanctuary on occasion, especially in the last few years, so they might have met during her visits.