Being a star silver won't get you any extra baggage allowance, but if you were OZ gold (star silver) and fly with OZ then you can check in extra 10 kg on top of free 20 kg allowance. They usually let you get away with extra 3 kg but 5 kg you are pushing your luck and make sure to be very nice to a person who is checking in for you....smile all the time. Hand carry is 10 kg. Good luck!