I'm not sure about this, but the way I see it working is everybody still has to be on the same package options. Which means while only one person needs the annual pass, you would need to buy tickets separately for everybody else in the room. You could however add the dining for everybody, so it really doesn't make a difference.
Either way only one person in the room needs to have an annual pass, and you can add dining for everyone. You might just have to order tickets for everybody else separately, or drop by a ticket counter on your way into the parks