United959-
Although I'm not positive, if memory serves the Entertainment coupons are not combinable with anything else.
Also, because ORD is a hub, the Entertainment coupon is only good for 5%, not the full 15%. So, us Chicago folks get the shaft with that coupon. People have gotten around this rule by flying out of MKE and ditching the last leg, but it may not be worth the drive/train ride.
Sorry I don't have better news
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"I just wanna wish you good luck, we're all counting on you"
-Dr. Rumack