I have a flight for SYD-NRT-BOS on JL in J (arriving in BOS at 1700) and then a separate ticket for BOS-YYZ on AC in Y (departing at 2045). If JL do tag the bag through to YYZ, does the JL checked baggage allowance apply for the BOS-YYZ segment? That is, do I just drop of the checked baggage at the AC counters in BOS and be off to the departure gate or will the AC agents charge the checked bag (and potentially overweight) fee before accepting it?