Catalysis of the reaction: H+ + NADPH + O2 + taxa-4(20),11-dien-5alpha-yl acetate = 10beta-hydroxytaxa-4(20),11-dien-5alpha-yl acetate + H2O + NADP+.
taxa-4(20),11-dien-5alpha-yl acetate,NADPH:oxygen oxidoreductase (10beta-hydroxylating)