if you want an alliance for only asgard and anchients. how abot you go to norse mythology since thts what the asgard are named from or vice versa.
Vanir ( anchient gods )
Aesir ( newer gods who came in and assimilated the vanir in with them)
you could name the alliance based on names of norse gods.
oh yes i forgot about the homes of the higher beings. in Norse mythology the word is split in to 3 worlds.... the lower realms being hell middle being of man and giant and the highest level being for gods and elves. depending on the source of your mythology
asgard is the home of the aesir gods. and vanaheim is homw of the vanir gods and alfhiem is home of the elves. I'm not sure of the spellings its been forever since i studied norse mythology.
so perhaps using names of gods old and new and or perhaps the home someone with more creativity can come up with a name.