I have had rooms with regular bathtubs. If you are looking for an oversized tub or jetted tub, I haven't seen any, but I haven't been in the suites.
Some of them have regular bathtubs if that is what you are referring to!
The 1-king bedroom has a bathtub with shower but not independent soaking tub, if that's what you are looking for.
Get an answer from Renaissance Chicago Downtown Hotel staff and past guests.