Ty mentions "the Owners" several times. They seem to be neither Red nor Blue and furthermore are hinted to have links to "the Purpose", but is it clarified anywhere who they are?
Ty the bartender doesn't know who the Owners of his bar are, and we the readers are never told either. All we know about them is what we are told through Ty's point of view and what he tells the others in the epilogue, which is not much (and you probably know it all already), but here's a recap:
- They're "ambiguous" in their affiliations with the Red and Blue factions – perhaps not belonging to any of them, or perhaps working across the ideological divide for a greater good ("Its ownership structure is … unusual. Connections to Red, I'm told." "One of the Owners happens to be of part Aïdan ancestry," Ty admitted, "but be careful of making unwarranted assumptions about where his loyalties lie.")
- They're wealthy and their organization is old – "very old money was behind the Crow's Nest" (the bar) – perhaps stretching back to before the Red/Blue divide based on the previous point?
- They know something about "the Purpose", a vague metaphysical philosophy or actual goal for mankind
- They behave differently – and generally better – than people who serve other masters (such as Red and Blue) than the Purpose
- They lend out rooms in the Crow's Nest for free for other people who serve the Purpose, and use it as a meeting place on the Cradle
- They pay Ty to tend the Crow's Nest, but also to observe "the human condition as it was so richly displayed from day to day within these walls" – they value the bar "partly as a cultural institution and partly because it gave them access to the sort of information about the lives, thoughts, and deeds of important persons that could only be had in a bar"
Based on this we can't know anything definite, but we can theorize, and some people have done so. There's little point in rehashing their thoughts here, but here are a couple of links:
- https://thedilettantesdilemma.com/2015/06/14/seveneves/ (in which the Owners are compared to a similar entity in Stephenson's novel The Diamond Age, suggesting not a plot connection but a similar concept)
- https://www.reddit.com/r/seveneves/comments/3b3p42/parsing_out_connections_to_anathem_ect_spoilers/ (in which a plot connection with Stephenson's novel Anathem is suggested)
Personally, I find it plausible that the Owners "know" something about the Agent that blew up the Moon (either factual or religious), and that they work behind the scenes to influence or guide humanity to their future, but we won't know for sure until Stephenson writes a sequel.