Board Thread:Metal Gear Solid V/@comment-65.49.14.165-20150308095403/@comment-25090680-20150308195938

Well IGN says so James176 asks: Will it import to The Phantom Pain when you complete Ground Zeroes?

Yes, POWs, Mother Base bonuses, and more statistical things will carry over. You’ll also get downloadable content bonuses of some kind that benefit you when Phantom Pain releases. The Phantom Pain will definitely know you’ve played Ground Zeroes. Plus, if you play on Xbox 360 or PlayStation 3, your save data will transfer to Xbox One and PS4, respectively.

That's about all I can find on it. Chances are though, if you can transfer between ps3 and ps4, you can do so between 360 and X1.

Link the IGN ask me anything.