I think signing masstricht treaty is an economic completion of political integrity for getting to be a union state .Countries that have not joined monetary union is probably on the status of federal cooperation based on being in the same region(neighbouring). So once you integrated monetarily then you can be bailed out in the sense of being one state as political integration completed, otherwise like UK and few other European states you can decide how far you want to take integration process/steps in the way of becoming "one state" union..
. In this case I wonder if those countries who have not joined monetary union(economic integration) can stay away from bailing out countries like Greece?