You now have the option to donate a booster to anyone on your team. Simply go to the team screen and tap 'Donate Booster'. You'll then be presented with a drop-down menu showing your teammates. You can choose a specific teammate to send a booster to or you can choose to send the booster to 'Anyone' and it will be claimed by the first teammate to tap 'Collect'.
From version 4.5 this feature is only available for players above 30k trophies.