It seems the ENT canon supports at least these Vulcan worlds:
- Vulcan
- P'Jem
- Paan Mokar (claimed, but apparently no permanent Vulcan residents)
VOY mentions another, which might or might not have been founded after the Federation:
Then there are several non-canon candidates I found:
- Cor Caroli IX - a few hundred Vulcans in the 24th century probably means it was founded after the Federation
- Trilan might be a major colony and is mentioned in both TOS and ENT material
- Merak II "Merak was one of the first worlds that was colonized by the Vulcan race"
- From Memory Beta on Vulcan history: "The Vulcans soon established colonies on worlds such as T'Khut, Kethri and Mevet"
- Darien 224
Finally, there's an article on Vulcan Space on alpha-command.com, the most important bit of which is quoted below. While the Alpha Command project claims that "We incorporate many sources of canon and non-canon elements into our group...", the article is unsourced, so it might as well be nothing but fan fiction. Some of the planet names gave no hits at all on Google, but others I could confirm on Memory Beta.
Vulcan space consists of approximately 26 star systems spread through out Federation space. The most notable are; the Vulcan system, the P'Jem system, the Nisan system, the 3 system Vulcan Colony space in the gamma quadrant and the 9 system colonies in the alpha and beta quadrants in federation space.