Catalysis of the reaction: dTDP-4-acetamido-4,6-dideoxy-alpha-D-galactose + beta-D-ManNAcA-(1->4)-alpha-D-GlcNAc-1-diphospho-ditrans,polycis-undecaprenol = H+ + alpha-D-FucNAc4-(1->4)-beta-D-ManNAcA-(1->4)-D-GlcNAc-undecaprenyl diphosphate + dTDP.
4-acetamido-4,6-dideoxy-D-galactose transferase activity