Each unit of local government initially adopting a concurrent resolution under G.S. 160A-470 shall become a member of the regional council. Thereafter, any local government may join the regional council by ratifying its charter and by being admitted by a majority vote of the existing members. All of the rights and privileges of membership in a regional council of governments shall be exercised on behalf of its member governments by their delegates to the council. (1971, c. 698, s. 1; 1973, c. 426, s. 72.)