Hello!

User should finish the registration by himself to be sure that the registration is real. So, the all information about referrer is stored in browser of the potential member and after his confirmation user is added to the referred list automatically. It means that if admin confirms the profile it will not work. But admin can add referral to this member manually via studio->affiliate system->members area. It will take the same take as profile confirmation via Accounts module.

We will update this algorithm in the next version and to make it possible to register user after admin's confirmation.