In Los Angeles, the city is close to approving a piece of legislation that would increase the city's minimum wage to $15 an hour by 2020. Surprisingly, labor organizers have asked that an exception be written in so that companies who employ organized labor do not have to comply with this new minimum wage. The organizers believe that unionized workers should have the ability to negotiate for what they believe is important, and in some cases this high of a wage may not be a priority.
See "L.A. Labor Leaders Seek Minimum Wage Exemption for Firms with Union Workers", Peter Jamison, David Zahniser and Emily Alpert Reyes, Los Angeles Times, May 26, 2015