When you buy the Valentine's Day offer, 300 Gems are applied to your account (same manner as all in-app purchases) and 30 Gems are gifted to your Alliance members. They can collect their gift from their in-game inbox. 

Why didn't I received the 30-Gem gift?

- Check your in-game inbox
- You weren't in the Alliance at the time of the purchase
- The buyer was not in the Alliance at the time of the purchase
- You purchased the offer so you get the 300 Gems - not the gifted Gems