I'm sort of in the same boat as the previous poster.
I've had my Hilton Amex for several years now. I recently opened a new Hilton Amex account for my mom (with me as the referrer) that is pointed to my HH Account #. I am now getting two monthly point dumps from AMEX. Unlike the previous poster, I *am not* an authorized user on her account.
I also got the referral benefit (10K) as well as the standard 20K (or whatever it was) for first time use of the new Hilton Amex card.
Not too shabby. Hope this helps.