Any public agency that has pursuant to the provisions of Section 20351 entered into an agreement to establish a reciprocal retirement system with this system shall be deemed to have obtained the same rights and limitations with respect to all other public agencies who have entered into those agreements and established reciprocity as well as with respect to county retirement systems and under Chapter 2 (commencing with Section 45300) of Division 5 of Title 4 that have established reciprocity with this system pursuant to Section 20351.