Ultra Violet Accounts are Seperate From FiOS accounts.
You can access your UltraViolet on FiOS but Fios doesn't know or care that you are using Ultraviolet.
So when you buy a dvd/bluray and do the digital copy, it's a transaction that only happens between you and them and that's it.
FiOS has their own on demand and flexview which is similar, but they don't have any 1080p content, 1080i is the highest that they have.