Been looking at cheap fares to the US and at present, FRA-DFW-LAX is going for around £255 with AA.

Seeing as that fare is AA's B class basic fare which awards no TP or Avios etc., does it make a difference booking it through BA.com rather than AA.com?

I did a dummy booking through BA.com and it mentions earning around 14k Avios and gives me the option to use Avios to reduce the cost.

If it will give nothing, does say BA from FRA-LHR and then AA in basic economy make a difference?