SPRINGFIELD — A group representing retailers’ interests has proposed an alternative to the minimum-wage bill that passed the Illinois Senate last week.The Illinois Retail Merchants Association this week suggested a tiered approach to raising the minimum wage in Illinois, citing concerns the current proposal could harm businesses.Senate Bill 1 passed through the Senate on a party line vote, Thursday. If passed and signed into law, it would increase the minimum wage to $9.25 an hour on Jan. 1, 2020. Then on July …