We lucked out and were able to eat at this rooftop at brunch. The rooftop is at the hotel we stayed at in Chicago called Chicago Athletic Association. One of us basically put our name down early in the day, and we eventually got in (14 people before us on the wait list).
Got the traditional brunch food… mimosa, and the Cindy breakfast (scrambled eggs, bacon, and potatoes). All were great and would get them again.
Also, the rooftop view is pretty good (you can see the bean from up top).