ENT "Minefield" casts that very much in doubt.
When Romulans communicate with Hoshi Sato in their own language, she hears them identify themselves as the Rumalin. T'Pol corrects that to "Romulan" - probably because that's the preferred Vulcan pronunciation, as Hoshi must have gotten the Romulan pronunciation right on the first take.
True, on screen that is correct. I was going by the Diane Duane Rihannsu