Metal studs absolutely must be bonded for safety. It's no different than I-beams in a commercial building. If the manufacturer has them UL listed for screws providing adequate bonding, that's great, that's easy, just bond each section to the highest ampacity circuit it's likely to be energized with.
Regardless of what's done for safety, the metal studs in a house should be grounded for lightning protection. Not so much to protect against a lighting strike, but to prevent one; ungrounded metal can become charged during an electrical storm and attract lightning bolts. Proper grounding of electrical systems and metal building components is a lot of why homes are only very rarely struck.
