How many transactions were made to purchase a bottle of beer using American Express?
bottle of beer refers to ContainerType = 'Bottle'; American Express refers to CreditCardType = 'American Express';
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'