Quote Originally Posted by Uesugi Kenshin
Well I believe Vulcan was merely the Roman version of him, so if they follow that then it should be. You should at least be able to change them to a temple of a new religion *Hagia Sophia cough cough*.
Well that was more or less what I said. If you take a Seleucid city with a Temple of Hephaestus as the Scipii then you can build a Temple of Vulcan afterwards when you have progressed to the next governor building.