Since Stephen's a big shot patron of Nate and is also uh
manipulating him with knowledge of the Cousin Secret
I figure this could go a few ways!!

Either Stephen swears Nate to secrecy about what he knows and invites Sam to occasional friendly private dinners in the Vorpal to discuss Nate's future and money and chat shit about the up and coming victors of the year

Or Stephen doesn't swear Nate to secrecy and invites Sam to fancy dinners he has no choice but to attend and play nice at anyway at risk of Nate's wellbeing

OR Sam knows or doesn't know but they mostly communicate electronically with occasional audiences strictly for business purposes

Or anything else that you can think of depending on your preference! I'm not sure if you and Alex have spoken about preferences on this, I'm happy to go with whatever - or with nothing if you'd rather Sam not have Cardinal Stephen Strange up in his business