Usually I see it spawn on like a 4/3/0, which makes it 7/6/3, which isn't any better considering there's nothing useful to build in the city. I don't think it can ever spawn on a tile with essence since I don't remember ever seeing resources spawn inside that wildland. Somehow it spawned on a 0 yield tile for you (did you change minimum yield values in the xml to like 8?), honestly I don't see that making a difference and I'm not sure it's a bug.

In my 0.75 game I had it with 5 essence, it was "Level 8" and popped the noise for level 9, but no upgrade screen.  Put some Darking and Wilding Shamans in there and make it a fight!  And then give us a spell as a quest reward to grant a 6/6/6 tile to build our own city.  

More neutral cities or creating neutral cities on faction defeat would be fun.

Wildlands have been getting no love. The reward for the Imperium is a spell and a 4/4/0 tile to build a city on. Also the rivers in the Imperium turn into plains but still look like rivers when you conquer it.

Wildlands should be 9 tile yield at least guaranteed.

and rivers/forests should NEVER become "not rivers/forests".