As far as I know, there is no evidence for more than the single universe that we live in. Any speculation to the contrary is only that and is backed by no evidence whatever. I feel that such speculation remains sterile until at least some evidence has been found for it. Until individual bubble universes are found, I wouldn't worry about what to call them. If someone wants to believe in bubble universes, I'll be content to let him devise a name for them. When I say "universe", I, too, mean the whole spacetime that appears to have come into existence 13.71 billion years ago. I, too, suspect that there is much more to the Universe than we know about or can even guess at at present.