If I remember, one of the supplement book explains that "covenant" designs: the place, the assembly of magi and the charter they have together.
As I say for the "charter/assembly of magi working together" alliance doesn't trouble me.
But in my sagas, we always use "covenant" for the location, and there, "alliance" is not really fitting.
But what a little piece of detail ^^.
after the amazing success of the "rulebook " for French ars' community , the translation of "Covenants" "true lineage" and "Arles"(A pure french production of 9 adventures in provencal tribunal)and two others books (selected later by subscribers) is launched on this side of the Atlantic !
you can follow at http://fr.ulule.com/ars-magica-printemps/
in addition, subscribers makes some suggestions of goodies for the true lineage sourcebook:
Fun!
Awesome! "Hermetic" dice and new content... Where do I have to sign to get something similar for Spain...?
by contacting Holocubierta, I guess 
Probably.
I have made (just for fun) a french banner equivalent to Atlas Games' one for ArM5, inspired from french editor Les Ludopathes' book cover illustrations [respectively from the Storyguide screen/parma fabula (TBA), the core book cover, Le grimoire du mage cover], following wishes and directions edicted by Djinfizz (thanks to him for his ideas).
The original version:
The french version:
So here it is…
(Unhappily, these two banners are not synchronized 
)