If you hit another player's base and did not receive Alliance points, ensure you met all of the following criteria:
You must be in an alliance.
The enemy must be in a different alliance.
The enemy must be your level or higher; if you are level 50+, you can hit any other level 50+ base.
You must do 50% damage in a single hit and, in that hit, you must destroy the enemy's Outpost.
If the hit is successful, you will see the points you earned in the post-battle pop-up window:
Note that these points can take 5-10 minutes to appear in your "My Alliance" window or the "Weekly Alliance Points" section of the leaderboards.