Not even worth waiting on hold to ask. The answer is almost always no. Amex flaunts restaurants like Eleven Madison Park as their global dining collection partners. They say you can only make EMP reservations through the phone concierge, not resy. Then, after you wait on the phone to see what they can do for you, they just tell you to put your name on the public reservation waitlist. Not sure why they couldn’t have just told me that in the Resy app?