If you click on the Air Altar the city it attached to is Ithuane. The outpost determines which cities control the resource. I don't mind this bug / feature, but it is something that isn't right with the game mechanics.
Don't take this post as a complaint, but more as something that needs to be told to new players. Think of it as a nuance about the game. The only way to fix this minor bug would be to add a new feature for outposts.
What really should have happened is that the qued version of the air altar should also have moved to the new nearest city that the outpost is connected. But I think in the long run that people would be more annoyed by the corrected version than this minor bug / feature.
But it is in a sense a cheat, because I can have an old city have 2 pioneers, one builds an outpost. I que up all the resoureces in that outposts range including all outposts upgrades, then build my closer city. The outpost changes control and I get the quick build on the new items and the new city is free to build up as usual. This is a loop-hole in the game rules as it were. Similarly when you are at war with a new neighbor. Before taking their city que up all the structures of the new outposts into one of your big cities before taking their city. Then you get to upgrade all the resources without dealing with the higher unrest.
A minor fix is to add production costs to resources depending on the distance between outpost and city to which it is connected. But that is a feature request and then one could add that the outposts be connected to any particular city of the players choice, and defaults to the nearest city, unless it is already connected to a city. Probably need a switch in the options for it to always choose the closest city for players that don't want to be bothered by such a mechanic.