California Code, Public Utilities Code - PUC § 95650

(a) If a majority of the employees employed by a transit district in a unit appropriate for collective bargaining indicate a desire to be represented by a labor organization, then the board after determining pursuant to Section 95651 that the labor organization represents the employees in the appropriate unit, shall bargain with the accredited representative of those employees. Both parties shall bargain in good faith and make all reasonable efforts to reach agreement on the terms of a written contract governing wages, salaries, hours, working conditions, and grievance procedures.

(b) A contract or agreement shall not be made with any labor organization, association, group, or individual that denies membership on any basis listed in subdivision (a) of Section 12940 of the Government Code, as those bases are defined in Sections 12926 and 12926.1 of the Government Code. However, the organization may preclude from membership any individual who advocates the overthrow of the government by force or violence.

(c) The district shall not discriminate with regard to employment against any person on any basis listed in subdivision (a) of Section 12940 of the Government Code, as those bases are defined in Sections 12926 and 12926.1 of the Government Code, except as otherwise provided in Section 12940 of the Government Code.