Yak and Yeti is awesome. It's a must do for us... you can ready my review on the link below... But.... if I was only going to Animal Kingdom Park 1 day, I'd probably only do a lunch table service (Yak and Yeti!)...so there's more time for park stuff. Since the park usually closes early, you could go almost anywhere for dinner... especially if you have park hoppers.
Ideas I'd consider after AK Park....depending on age of children and energy level...
Take the bus from AK Park to another resort for dinner. In 2009, we took the bus to AK lodge and enjoyed Jiko.... Bus was only about 10 minutes.... we took a taxi back to our resort. Or better... take the bus to Ft. Wilderness with a Hoop Dee Doo dinner reservation....after the show, take the boat ride from there to Magic Kingdom, then bus to POR. (I like the boat rides and don't mind taking the extra time).
Take the bus to one of the Epcot area resorts (Boardwalk Inn, Beach Club, Yacht Club) for dinner. There's mini-golf courses by Swan and Dolphin resort, and entertainers (magic, comedy, juggling) on the Boardwalk in the evening. I don't think a taxi would be expensive from here to POR, not that far.
Go back to the resort for dinner. Call it an early evening and get up extra early the next day for a park.
Downtown Disney? - Never been there but that's an option I'd consider.