This is the opening conversation of Dreamy between Nova and Blue.
Blue Fairy: Easy!
Nova: Sorry.
Blue Fairy: Careful. Careful. Fairy dust is the most precious substance in all the land. Its magic is what powers the world. This is the year’s supply – we must be cautious.
Nova: I know.
I don’t think they ever talk about fairy dust being used to travel between worlds. I have no doubt that it CAN do that, but thus far it has not been established. I also have no doubt that fairies themselves can travel between worlds but again, it hasn’t been shown or discussed. I really want to see Blue travel between worlds. I had theorized that Blue was responsible for getting Bae out of NL and into our world but Neal came to our world in 1991, a few years after the curse hit.