Those aren't quite as picky about high light as the (real
) Vandas. I agree, supplemental light would be helpful especially in the dark, gray days of winter. But they should do fine with that little boost. I wouldn't stress about the humidity too much, especially if they're potted. (if mounted, you could just pop them into a pot, mount and all, and just fill in with some bark)
(Something a bit weird, I wrote this after I read ES's post, but it got an earlier timestamp... so read accordingly)