The Windy City has recently posted updated guidance on its website to explain the various requirements and procedures put in place since the $0.07 checkout bag tax took effect, on February 1, 2017. Though retailers are not required to, most are likely to pass the tax on to consumers.
Normally, the wholesaler who sells checkout bags to a store is to collect the tax, but if a store receives bags from a wholesaler who has not collected the tax, the obligation is on the store.