Erik Oberholtzer, co-founder of the L.A.-based Tender Greens chain, which has 18 units including three in the Bay area, said his company has been preparing for minimum wage increases for some time. The chain already pays above minimum wage where it operates, but with hourly rates rising, so does the challenge of staying above the minimum, he said.“If the minimum wage is $15, we’ll pay $16 or $17, so hopefully we’ll get better people and that will result in better operations,” he said. “But as much as we joke about how people voted for it so they should pay for it, it just doesn’t work that way.”