It runs back and forth constantly, but I'm not sure of the hours. But it's not like "every hour on the hour" or anything like that. Drives to one area, waits for a few minutes, drives to the other, waits a few minutes... you get it. It's now a nice size small bus (like a church or daycare bus if you're familiar). I saw it a couple times while waiting on magical express.
Also you can use the parks buses to go from Kidani to Jambo and the Disney Springs bus to go from Jambo to Kidani. Of course I would recommend checking with the driver to ensure you don't end up on a wild detour!
I'm not sure of your party's mobility but I timed the walk from Jambo front door to Kidani Zazu elevator over the weekend and it was 4 minutes. Mind you, you still have to walk a fair distance down the Kidani corridor after you get inside after the 4 minutes walk but there is air conditioning!
We finally did the Sanaa culinary tour and really enjoyed it. Our host, Chikanda (sp?) from Zambia was so sweet and knowledgeable. We learned a lot about the art in the restaurant and were treated to a sample of three different types of bread and three dips (from the Sanaa bread service) and a quick visit from the chef after our tour of the restaurant. Total time including snack about 30 minutes. Totally worth it! (It's free!)