No tax on daily allowance. I am now 14 years with KLM (/KLC). The annual gross total is from 2008, just checked the overview to be sure. Income is split in parts, for the amount more than 54000€, 52% tax was paid in 2008.
I am sure the BA captains will start feeling better again when the GBP goes up, meanwhile I will buy them a beer in Dusk til Dawn...