Just to be pedantic, we don't really know for certain that T'Paal is on Vulcan. (It seems almost certain to me, but for the sake of argument...) The exact quote is as follows (From VOY: Unimatrix Zero, Part II):
TUVOK: My daughter's name is Asil. She was born in the city of-
BORG QUEEN: -T'Paal. We share your memories.
It was never actually stated here that the city was on Vulcan. Rogue Vulcan 02:05, 12 May 2008 (UTC)