BBPress VS Membership Users - do they need to double-register?

Hi all,
Me again - sorry if I'm being nuisance!
I have set up quite a nice Memberships thing, but am now working hard to get together a bbpress forum.
I was wondering: if someone signs up for a Member account using the Membership plugin, does the bbpress forum recognise them as a member, or will they have to register for that as well?
So far my Memberships plugin protects the forum pages from non-members using a Group URL shadow (domain.com/community/forum/*).

Hope that's clear and if anyone can answer soon, great stuff! I'm on a role!
Ben