There's nothing in the current storylines to suggest that Harper and Rowan are returning to Bray, or that Bo is going to join any of them. Harper and Rowan reunited does mean they're going back to Wyatt, it means they're back as a team. Unless I missed something and Wyatt has been giving promos or tweeting about followers or something along those lines, it's not happening.
Logical and natural storytelling would have seeds planted that these things are coming. Bo interacting with Ryback before Bray isn't a seed unless the two real life brothers have a moment of acknowledgement, which they didn't. But this is WWE and logic doesn't matter, so these guys could be a stable next week. I think it's probably the least likely thing to happen any time soon.
The Wyatt Family was broken up so Harper and Rowan could become singles stars. Rowan flopped as a face, and Harper wasn't given enough time. Together they can be an excellent heel team, but I have to ask, is this a tag team reunion we're truly seeing?
Since last Smackdown when Rowan attacked Fandango, they've competed in singles matches. Rowan came out to Harper's theme, which was their theme as a team, but still with Harper's eyeball graphics and not team graphics. That could just be WWE being lazy or waiting or whatever, but this could be an alliance of the two men with Rowan the lackey to Harper's single stardom.
A reunion of the tag team seems the most likely option, with a step in the right direction for both men. A reunion with Wyatt would be a step in the wrong one for Bray, if only because he needs to be this "new face of fear" and to be scary, he needs to win on his own.
Harper and Rowan will win tag team titles and stay in the tag division for a few years. The earliest they should win the titles should be in the early fall, so as not to derail New Day's heat and momentum. I would enjoy feuds with PTP, Lucha Dragons, New Day, and especially Kidd/Cesaro. I think setting up a future feud between Bo and Bray with Harper and Rowan becoming Bo-lievers could be interesting, but I'm not sure WWE sees Bo's star as high as Bray's.