I do not travel that much, but I am flying from YYZ to SYD on Quantas via LAX. The YYZ LAX leg is via American Airlines and given the huge amount of miles available I want to collect the miles to put towards a domestic flight. Wondering if I could get some advice on whether I should sign of for AA Advantage or Quantas' frequest flier program?

Also, I will traving with my 3 year old son that I have bought a ticket for at 75% of the regular ticket price. Can I accumulate points for for him, or can he accumulate his own points?

Thanks!