Originally Posted by
Rusdude
Based on reading reviews of other Hyatt all-inclusive properties, you should be able to get a paid upgrade in advance by contacting the hotel or doing it during check-in. Not sure about Los Cabos, but Zilara Cancun also sells packages which include upgrade + some other perks (like dinner on a beach).
Gold Passport said that was not possible...maybe the old fashioned "upgrade request" a (well placed high-denomination greenback) might work...