PS3 and PC

[ThusFarJay]

You would need to purchase the PC copy as well to play between both platforms.

Logging into the Same Account on both Windows and PlayStation 3
It is possible to play with the same account on both Windows and PlayStation 3 platforms. Customers who own a copy of FFXIV for Windows and wish to use their account on the PlayStation 3 version will need to purchase a copy of the PlayStation 3 version. It will then be possible to use your characters on either platform by tying your existing service account to the PlayStation 3 version upon launching it for the first time. Similarly, customers who own a copy of FFXIV for PlayStation 3 and wish to use their account on the Windows version will need to purchase a copy of the Windows version. However, please note that your account will only be able to log into one platform at a time.!

Source under Importnat Notices