You can only play early access with the system you selected when the option came up when you entered your pre-order code. So you can only play early access on your PS3. When you get your game code to your PS3 came you follow the activation procedures which will eventually have you login into your square-enix account with your 1.0 status. It will link your games if you add it to the service account that has your 1.0 game on it.

TL;DR - You can only play early access on the system you chose when you entered your pre-order code. Account linking does not happen until actual release using the retail game code.


Cheers.