We don't know if he's related to Booster anymore or if they in fact have a working relationship. The only clue we get is this mention in the JLI Annual.
Now the annual confused the hell out of me for multiple reasons, chief among them the fact that very little of the story gelled with Jurgens JLI. I wasn't sure why Booster (both of them) disappeared since present day Booster does so after Clark and Diana kiss. Since I was distracted by all the retcons and everyone remembering him despite the fact he was erased I forgot this detail. According to future Booster Rip was following him to erase the conversation. Booster still exists though and showed up in the past with some memory loss.
Which means one of two things: 1.) new 52 Rip is a bad guy or 2.) Booster is trying to fix something that can't be fixed/shouldn't be messed with.
The second choice makes more sense based on who Rip was but we'll see how this plays out. Notice future Booster is also wearing the same outfit he does in his Futures' End cover.