I'm sorry if anybody actually read my spoiler without wanting to. I thought if I revealed it was from Trek XI, it would be too obvious. I fixed it.
Well, according to Memory Alpha, which cites several episodes of Voyager, he was born on the Vulcanis Lunar Colony.
We don't know exactly where that is, do we? We do know that Vulcan has no moon of course. So it can't be in Vulcan orbit. If it were, my spoiler would apply.
Well, the problem was always to reconcile what Spock said in TOS ("Vulcan has no moon") with the very obvious celestial bodies in Yesteryear and TMP (theater's cut). It may sound silly, but I always like the explanation from Spock's World: the bodies are Vulcan's sister planet (the name was T'Khut) and its
moon (which name I can't remember), complete with the quote: "Well, techinally, Vulcan has no moon." "Damn right it doesn’t, it has
." So the Vulcanis Lunar Colony could be on that
body, and everything would fit.
The fact that Vulcan had a twin planet could even be linked to why
the Romulans choose a double planet to settle on: it would be the most similar to their own.