It's separate to keep the databases intact better.
The PG was created before the new member area, but we added the functionality to be able to login to it seamlessly from within the member area.
If all you want is access to the PG, it will show up in your member portal if you get it. However, it's also included with an All Access Pass, so you may want to consider that for all of the other things that comes with the AAP.