They probably book straight across OS-UA.
sbm12 is correct though, the only way to be sure is to contact OS after booking. UA will have no idea.
For TATL, S accrues at 100% on AP and T accrues at 50%. For intra-Europe, S accrues at 25% and T accrues at 0.
AP Accrual Chart.
Note that OS S and T accrue at zero on UA.