 Bau ceased as Tortosa mayor in 1930; in 1931 he was accused of financial irregularities, though none of the charges raised has been concluded.As three Traditionalist branches united in 1932 Bau resumed his service to the legitimist king rejoining the Carlist organization, .Within its structures he was heading the local Tortosa Requeté; as member of the Tarragona branch he had to accept leadership of the provincial jefe, Juan Maria Roma.