Alliance doesn't have a formal ranking system for the player yet. This was also true for FFE back in the day (indeed, the Alliance didn't have much of a formal navy in 3250 even though they managed to wrest control away from both Feds and Imperials a few decades prior), but maybe in the future if FDEV implement more military power for the Alliance?
Then again, I remember DBOBE described the Alliance as akin to the European Union in an earlier dev diary, and given the EU doesn't have a military like the USA does, I suspect it's more likely that member states to the Alliance will have their own military forces, and hence (although I have no idea if this is true for EU membership terms) will have agreements to provide resources in the event of an Alliance-wide military action?