Share buddypress database among sites

Hi!

I have a corporate website with a BudyPress installation.

Afterwards, my customer decided to create a subdomain with an intranet theme based on BuddyPress (WOffice).

My customer′s users are created a BuddyPress user profile in the main site, but if they want to upgrade, they will have access (user credentials and profile) in the intranet where they have extended options.

1. I′ve read many forum questions but still not sure whether this plugin or (Network+) will allow us to share buddypress users among both networks, knowing one of them is a subdomain.

2. We did not think it was necessary to set up a multisite in neither domain. Must we do that?

Thanks a lot for your support ;D