Catalyzes the reduction of dTDP-6-deoxy-L-lyxo-4-hexulose to dTDP-6-deoxy-L-talose. Can use NAD(+) or NADP(+). dTDP-6-deoxy-beta-L-talose + NAD(+) = dTDP-4-dehydro-beta-L-rhamnose + H(+) + NADH dTDP-6-deoxy-beta-L-talose + NADP(+) = dTDP-4-dehydro-beta-L-rhamnose + H(+) + NADPH Belongs to the NAD(P)-dependent epimerase/dehydratase family.