If the show is all ages do I still bring my i.d

Yes, if you want to drink. They have a pretty sweet set-up in there for bars! Love the Fillmore!

For practical purposes, always take your ID. If something goes wrong you'll be glad you have it. IDs have saved lives of unconscious people. And allowed notification of family in the event of injury. Your phone is likely locked and useless to first responders. But your ID could make all the difference.