If it doesn't list this under promotions, it will not count:

"Any video game purchase of $19.99 or greater on Amazon.com will qualify you to receive an Amazon promotional code that will grant you three exclusive pieces of DLC for Final Fantasy XIV: Stormblood! Codes will be sent 48 hours after purchase. Here's how (restrictions apply) "

Make sure you're pre-ordering through amazon.com (amazon.ca is not taking part in this promotion). There's a limit of one code per amazon account as well so yes you will need two amazon accounts to get two codes.