That's done on purpose, I don't know if they gave them credit or not on the album, but Bon Jovi will never sue them! Every song is a rip off of some eighties hits, they're all happy with it and often join them on stage in LA and do covers. They were born as a comedy cover band taking the piss on these bands, but in a nice way, nobody ever got offended and it's been going on for over ten years... If you're taking Steel Panther seriously you're missing the point
Check out their "Behind the Music" video on MySpace, maybe things will be clearer!