The rules do say that 4 people could get b'fast if properly registered. Per the GP T&C's "In Hyatt hotels that do not have a Regency Club or Grand Club lounge, daily complimentary full breakfast (tax and gratuity included) will be provided to the member and each guest registered in the room, maximum four (4) people." I'm assuming, in the case of the Park Hyatt Milan, that there is not a Regency Club or Grand Club lounge. I would be interested in hearing if there is some exception to the GP T&C's at this hotel.