Commencing October 1, 2006, any pensioner or annuitant who retired prior to October 1, 2005, from a city, town, county, or public or quasi-public organization of the state before the city, town, county, or public or quasi-public organization of the state became a member of the Employees’ Retirement System and is receiving a monthly benefit not administered by the Employees’ Retirement System shall receive the cost-of-living increase of two percent in his or her gross monthly benefit which the Legislature committed to in Section 14 of Act 2005-316, plus an additional five percent increase in his or her gross monthly benefit. The increase shall not be less than twenty-five dollars ($25) per month. The increase shall be granted provided the city, town, county, or public or quasi-public organization of the state elects to fund and pay the increase.