It's more or less a free for all. The only trouble I've ever had taping was for Radiohead and the Police. Both sets we were right up against the rail all Saturday, and just moved over 20 or so feet into the crowd and dropped our stand low. No problems and the tapes of both sets sound incredible. For the taper friendly acts, you can run pretty much as high as you want, right against the rail in the center. As long as you're not in a camera's view you're fine.
Like BC said, sunscreen is your friend. Bonnaroo can be a tough festival if you don't pace yourself and keep yourself hydrated. See you there!