I believe for Maddox to start appearing as a job you must have high muscles, musk kink active, and not be human or feline. I don't think sub or dom is needed.
Then to unlock his time at the club, you need to have played with him at Boss' night works. Stryker or Rohan's storyline does not effect Maddox in any way.
There's another way to unlock the club with the Black Panther, or one of the imps. But seeing the club is just something extra, it's not a location that will be actively explored until it's actually open. Right now you just see Maddox and an imp you see at the rat bar.
While getting some boss jobs there, which should be unlocked through Girardo after the storyline with Stryker and Rohan. You are missing a bonus scene with Dual and Maddox, but it's not needed to unlock anything. And the imp you see at the bar, you can't do much with him at the club.
The club right now isn't going to hold much of anything till it's brought up in the MSQ.