My achievements aren't being posted in the alliance chat like the other members and I hoped it would...

I've had the same complaint. Only certain achievements are posted by the game. Ex. Glory Level upgrades divisible by 5- upgrading to 29 won't post but upgrading to 30 will. Or once you start reaching higher levels the game isn't as impressed when you kill a new zombie level and stops posting those entirely. The milestones for posting get further apart also. I don't expect a new might level announcement for me to post tell I hit 1 billion might