If you were traveling on the same PNR I believe that officially you would be able to each bring 3 bags of up to 70 lbs each for free. But since you are on separate PNR's they may enforce the rules on you separately which means you can bring 3 @70lbs and he/she can only bring 2 up to 50 lbs. Now I have a feeling enforcement of this is all over the board because it's probably not something the agents will see every day and you may get an agent who allows you 6 bags @70 lbs. Good luck!