NEW CODE - EEYLFLN4 I scanned the image code with my phone and it popped up. Try it, not sure if its multi use, report back.
The QR code is in the FAQ as a sample so i scanned it, it points to http://qr.prizelogic.com/T$$$H and auto enters the code above in the slot.
This is the site: http://adventure.subway.com/
As of now Naughty Dog is not confirming this promotion on Twitter and no subways have any knowledge of it...