I answered this question via email. I post it again here in case someone has the same question
Hi Joshua
Yes. That's exactly how it works. Users will just have to have one user account and use that same account in the two extensions(and actually, all other extensions use on your site). Further more, the two extensions are nicely integrated together:
1. You can map the field between Events Booking and Membership Pro so that when users subscribed via Membership Pro, then register for an event in Events Booking, the data from his Membership Pro will be used to fill-in registration form in Events Booking automatically (so that he won't have to fill-in this data again)
2. If you even needs more integration, you can config the two extensions so that when users subscribe for plans in Membership pro, they will receive discount when register for events in Events Booking