Yes, the Gothic literature of the 19th century is still prevalent in Gothic subculture of today. One poet that some do not believe to be Gothic is Edgar Allen Poe. To this day, his dark way of thinking and writing is still alive and well, this is why it is still taught in schools as simply classics.
Yes, I think that Gothic literature of the 19th century continues to influence modern Gothic culture, because people who are into the modern Gothic culture, look at the literature that was produced in 19th century for clues and retro ideas. This is no different than the modern literature enthusiasts that read Greek literature for inspiration.
Gothic literature of the 19th century was extremely thought provoking and well thought out. It also had strong underlying themes that can be applied today. Today's Gothic culture can be accredited to whiney self hate and bad dress. Saying 19th Century Gotic literature and today's Gothic subculture are alike is like saying that Nickelback and Rush are the same type of band because they are Canadian.
Aside from some really horrible death themed poetry, there's not a lot of sameness between Gothic literature of the 19th century when compared with the modern Gothic subculture. Dressing in black, wearing white pancake makeup isn't exactly the hallmark of a literary movement. And seriously? The whole Goth thing went of style in 1998.
I really doubt that Gothic literature of the 19th century influences modern Gothic subculture. The Gothic subculture is actually quite small and many adherents are simply young teenagers trying to find their place in the world. For the most part its a different way of dress than anything. I doubt many of these people even read 19th century literature, much less are they influenced by it.