The single Code that was provided with the ultimate collection unlocks all content.

Simply log in to your square enix account page, go to "select service" select "Play Online/Final Fantasy XI" Click on "Add a service account" and enter the code that was provided.

The same applies for the two codes for the Destrier Beret and the Chocobo Shirt. Those items are wonderful to have for any jobs you wish to take from 1-30, and doing any of the existing level capped content at 30 or below (BCNMs).