I logged into Team 45 mins into the set, logged out, and then logged back in after 18 hours - got no bonus turns.

I don't think that's a bug, I think you never get a bonus until the set is 24 hours old. Then you can get an 18 or 12 hour bonus depending how long ago your last log-in was.

I snagged an 18-hr bonus last set in Team doing the same thing.

that oughts to be purpled, CX.

Yeah, I've got bonuses earlier before too, somehow, but then when I don't get it, and I report this issue, I'm told you're not supposed to get them except as I described earlier.

Hrmmmmm

/me not impressed.