Final Fantasy X/X-2 HD Remaster won't reach North America and Europe until March 2014, and that date is for the PS3 version only. As it stands, the PS3 HD compilation of the two RPGs hits North America on March 18, 2014, and then Europe three days later on March 21.
We've reached out to Square Enix about the Vita version, which like the PS3 version was originally due in the west later this year. Square Enix's website for the game still lists it for Vita, but today's announcements specify the PS3 version only. Final Fantasy X/X-2 HD Remaster is due on both PS3 and Vita in Japan next month, on December 26.
Update: We've received a press release from Square Enix Europe, and it notes: "Full details of the PlayStation Vita version and release timing will be revealed at a future date."