For Bolt, how about Thundercracker? Or maybe Volt? Or perhaps Juice (as in "Give it some juice!")? Hmm ... Negavolt, Megavolt, Megawatt, Kilowatt, Kilovolt, Arc ...
As for group members ...
Some kind of shifter ... shapeshifter, size alteration, etc. is very handy Perhaps the brick could be someone who shrinks and gains strength as he does?
A Gater, as in someone who opens gates, is also quite useful. Who needs a team jet when Portal is here?
For the martial artist, how about someone with animal abilities? Like a cat-warrior. Or how about someone like Jin from Tekken who has some dark chi abilities?
Gotta have an alien of somekind as well ... JLA have the Martian Manhunter ... the Avengers have the Vision (as well as a plethora of other aliens). Maybe that could be your mentalist or even a martial artist, specialized in an alien martial art?
Hope these ideas help