Is there likely to be a problem with domestic luggage restrictions being less than international luggage restrictions? Or... Are they likely to go easy on me since most of the domestic travellers will be travelling light and I've just got off an international flight?

I could book the whole thing through one airline so I wouldn't need to get luggage and then check it in again but I'm flying on someones airpoints and he said it needs to be Quantas from Aus. to US. And then American within the US because of the way the airpoints work...