My question is as follow:
I have an itinerary ticketed from SLC - LAX on UA, LAX-PEK on Air China, PEK-SGN (Stopover in SIN) on SQ
Since I'm a *A Silver (UA Premier Associate), Air China allows me to check one extra baggage at LAX (UA only allows 2 x 50 lbs). SQ doesnt give any extra baggage allowance to *A silver. Will Air China be able to check the extra bag at LAX all the way to SGN without fee?

Thanks