Every school district board of directors may establish an attendance incentive program as provided for in this chapter for any or all certificated and noncertificated employees: Provided, That the terms and conditions of an attendance incentive program for employees represented by a bargaining representative pursuant to either chapter 41.56 or 41.59 RCW, shall be established and implemented in accordance with chapter 41.56 or 41.59 RCW, whichever chapter is applicable.