As discussed, AAdvantage does not charge for other airlines fuel surcharges and taxes. Many taxes are based on the revenue amount and when its zero, there isn't much tax to pay for. But when other non-North American airlines ' programme come into the picture, they sometimes base their tax on the full revenue amount of what say a full J class seat would be and they take the tax from that.

Yes, if you redeem on any programme outside North America, ie BAEC, CX, QF, JL, AY etc on any partner airline, you will pay the full amount of taxes & fuel surcharges - depending on the airline or route of course. eg, currently CX flights out of HKG have lower fuel surcharges and taxes than on either BA or QF to LHR, or JL, CX flights out of NRT also have lower fuel surcharges than either BA or QF.

SO generally speaking, both BA and QF charge for their fuel surcharges even though their partner airlines may not. Bear in mind too, that if you redeem an AA ticket using asiamiles, you will be charged their fuel surcharge!