Alex Winter's next documentary "Deep Web: The Untold Story of Bitcoin and Silk Road" will be produced by Marc Schiller, founder of the Wooster Collective which list Banksy under their artists.
On top Schiller's company Bond Strategy and Influence was involved with the marketing on "Banksy - Exit through the Gift Shop" and he is surmised to be a close friend of him.
I'm sure if banksy isn't involved in bitcoin he has already heard of it and is watching closely.
Banksy painting a Bitcoin logo onto a parody of something would be great exposure / advertising. I hope it eventually happens.