Originally Posted by dhuey

Both options involve re-clearing security. There is an airside connection from T1-C (Delta) to T2 (Alaska, American), but that won't help you here. Keep in mind that you can't walk directly from Terminal 1 to International-A, where the Air France lounge is (Priority Pass). You would need to take the AirTrain red line one stop. The AF lounge is nice, but the food/drink options are pretty ordinary.

It's a relatively short walk from T1 to T3, but as noted above, this means re-clearing security. Whether that's worth it to you depends on how much time you have and how much you value the $28 credits for SF Giants Clubhouse and Yankee Pier (okay options, but nothing special).