Wintrust did make a offer but Guaranteed Rate beat it by adding in extra payments that would go to JR instead of the ISFA:
https://chicagoagentmagazine.com/2016/09/01/guaranteed-rate-paid-white-sox-stadium-naming-rights/
More than mere naming rights
Crain’s noted, though, that Guaranteed Rate’s deal with the Sox encompasses more than just naming rights. In addition, the lender signed a sponsorship agreement that covers “various branding, promotional and hospitality benefits, along with joint marketing opportunities,” according to a statement Crain’s cited; one such sponsorship the team has already promoted is the SoxFest convention in January.