How are the Star Wars prequels reboots in any way? They don't de-canonize the films they take place before, as Batman Begins and Casino Royale do.
And I don't know where all this "sequel" reboot/"prequel" reboot business is coming from. A reboot is a reboot, plain and simple. None of the Bond films are reboots except for Casino Royale. They just have very "fuzzy" continuity.
Think of it this way - is every episode of The Simpsons a reboot? Of course not, it's (in its own way) a "sequel" to the episode that came before it. But how can Bart have stayed ten years old for 21 years?! "Fuzzy" continuity, just like Dr. No through Die Another Day.
And the new Star Trek is still a reboot, it's just that the rebooting is built into the story, unlike Casino and Batman Begins, which simply pretend anything before it doesn't exist.