I would really appreciate some advice on what program is best to join.

A friend who is Brazil-based is going to be living and going back and forth between South Africa, Germany and the US over the next 2 years with a good deal of frequency. She has not joiend an alliance yet but Star would seem like the natural choice because of SAA and LH for FRA-CPT flights.

Which program would you guys recommend for her to join? She can do a US program if that is the best as far as redemptions and perks. I am EXp with AA and find US carriers tend to be more generous with benefits, status and redemptions than their foreign counterparts. Would it make most sense for her to join UA/CO, LH, SAA or TAM?

Thanks!