The allowance provided by

Section shall be paid with respect to a local miscellaneous or local safety member whose retirement was effective prior to his or her employer’s election to be subject to the

section with respect to employees in his or her employment, if at retirement he or she did not elect the optional settlement in

Section 21456, 21457, 21459, 21475, 21475.5, 21476, 21476.5, or or an optional settlement involving life contingency in

Section 21458. The retirement allowance payable to a retired member who elected any of these optional settlements, or to a beneficiary of a retired member, shall be increased by percent, for time on and after the operative date and prior to the next annual adjustment under

Article 3 (commencing with

Section 21310) of

Chapter and the base allowance shall be increased by percent for purpose of that and all subsequent annual adjustments. The amount payable to the beneficiary under the optional settlement shall be increased by the same percentage and in the same manner as the increase provided for the payment to the member. The increased allowance provided by this

section shall not be payable to a beneficiary who is receiving an allowance pursuant to this

article or

Article 4 (commencing with

Section 21350) of

Chapter on September 29, 1980, until the employer of the retired member elects to be subject to this

section as so amended by amendment to its contract made in the manner prescribed for approval of contracts, except that an election among employees shall not be required. In the case of contracts made on or after September 29, 1980, the operative date of

Section 21624, for purposes of application of that

section to local members, shall be the effective date of the contract or contract amendment.