Yes! It's technically the same resort and you are free to wander between the two and use the facilities at either one - yay!
We recently stayed at Kidani and used the pool at Jambo a few times for a little change, ate at The Mara, wandered around the Jambo savannah etc.
When you check in, you will be given a guide map showing the whole resort, and the CM will explain to you what is available at each place, how long it takes to walk between the two about (10-15 mins), and even draw a little line of where to walk. Or at least the CM checking us in did!
And if you don't feel like walking between the two -
catch a DTD bus @ Jambo and ride it up to Kidani.
Catch a park bus @ Kidani and ride it down to Jambo.
And if you don't feel like walking between the two -
catch a DTD bus @ Jambo and ride it up to Kidani.
Catch a park bus @ Kidani and ride it down to Jambo.
We were there end of May/early June last year and again just a couple of weeks ago, the gate was never locked even when we'd go around 11:00-12:00 to soak in the hot tub after a long day of walking. Guess it depends on the time of year?