Romulan is a clone only strain. Any seeds you saw or had were fakes. They might have been good, but they weren't Romulan. They were seeds sold by someone capitalizing on the name Romulan. Federation and Next Generation Seed Co. sold something they called 'Romulan' for a looooong time, but it's a Romulan Hybrid, Romulan S1, or a waaaaaaay underworked IBL at best. Almost universally bad reviews on these seeds, that's why you don't see any clones from these supposed 'Romulan' around today.
The *only* way to turn a clone into a seed line is a HUGE and LONG inbreeding operation involving thousands and thousands of plants. Because nobody's doing this for legal reasons (save for Sam the Skunkman and a few others), clone-only seed lines simply don't exist.