#2 - Sept. 28, 2010, 6:45 a.m.
From what I can see, Nectanebus, it looks like a trial account was created before the Recruit a Friend invitation was sent. The standard non-RaF trial account would be listed as WOW1 on the account, this is the account that was upgraded to a standard account and then with Burning Crusade.
WOW2, is the Recruit a Friend trial account, which was not upgraded.
Your Brother will need to contact our Billing and Account Services department during business hours. Since the account was recently created they may be able to transfer the link or account upgrade to the appropriate account and allow the two of your to start gaining Recruit a Friend benefits.
You can call 1 (800) 592 5499 (1-800-59-BLIZZARD) 7AM-8PM (PST/PDT) for live representation.
Australian users should please call 1-800-041-378 if the standard 800 line does not work.