I already booked the rooms and now we decided that we might want to do some of the grand gathering events (we have 10 of us going), do I call member services for this or the regular Disney number?
Call Member Services. Given them all of the names, addresses and ages of the members in your party, nothing those who are not adults. MS will contact the grand gathering (GG) people and get a Grand Gathering number back to you. You use this number when booking GG events.