It seems from the T&Cs you can combine GP points from 2 accounts. Note you can only do a transfer from one account to another to redeem an award and you can only transfer the number neccessary to get the award.

As far as redemption, under the T&Cs the redeeming member must be present at checkin to present a photo ID and credit card. I think this limits your ability to book a room for a third party to those situations where you are traveling together. Others may have experience with being able to redeem for third parties when not present but I haven't tried to do that.


Combining:

http://goldpassport.hyatt.com/gp/en/...&cat_id=16&wt=


Redeeming:

http://goldpassport.hyatt.com/gp/en/...&cat_id=16&wt=