CEDAR RAPIDS — In less than three months, the minimum wage in Linn County increases a dollar an hour to $8.25 in its eventual climb to $10.25 by 2019. But not all cities in the county are likely to force businesses within their boundaries go along. Last week, for instance, the Robins City Council approved the first of three considerations of a measure to stick with the existing state and federal minimum of $7.25 an hour. “I think our concern is that unless it’s dealt with at the state level, we will end up with a patchwork of minimum wage regulations scattered across a number of counties,” Robins Mayor Chuck Hinz said afterward.