If this was a DL codeshare I'd say your chances would be 100%. I've never missed an upgrade on AM but my flights are usually MEX or GDL to LAX.
I suspect the MEX/JFK route would attract a substantial number of Mr. Big's...Senor Big's in this case

...and the redeyes to New York are pretty popular. If your flight is on a 757 with a lot of FC seats then obviously your odds of snagging an upgrade improve.
AM really doesn't have to acknowledge your status on a non-codeshare flight but it wouldn't hurt to flash the credentials and hope for the best.
Good luck!