Write SQL query to solve given problem: How many transactions were made to purchase a bottle of beer using American Express?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(T1.RootBeerID) FROM rootbeer AS T1 INNER JOIN `transaction` AS T2 ON T1.RootBeerID = T2.RootBeerID WHERE T1.ContainerType = 'Bottle' AND T2.CreditCardType = 'American Express'