In any one of your cities, the Alliance Base is located on top of the hill beside the Embassy building, overlooking the Golden Tresure spot.
Here are the buildings inside the base. I wonder how these budings and the cave can be placed in that buding you saw located on the hill in your cities, huh?
Anyway, the Alliance Vault allows you to redeem some stuff with your Alliance Resource.
With your Alliamce Resource, you can recruit Alliance Guard whose excellence in guarding your cities. Before recruiting them, alliamce leaders or ministers have to train them with available Alliance Honors.
The Alliance Tavern is where one gets his Alliance Honors and Resources. Complete Common Tasks, Rare Tasks and Epic Tasks to receive different numbers of honors and resources.
An example of a completed task in the tavern that rewards honours and resources. All of the above buildings could be upgraded with enough Alliance Resources.
The Alliance Portal allows Goblin summoning by the Alliance Leader or Minister. Goblin camps will appear just next to your main city, but not all members of the alliance will get the Goblin camp. Attacking the Goblin camps will give you more honours and resources than completing tasks in the tavern.