If you are asking technically whether Hibernate calls have to be in a transaction, the answer is no. Each call (update, insert, or delete) will be done as an atomic action. After the function returns the request to the database will be complete. When the database actually commits the change is up to Hibernate, the driver, and the database itself.
If you are asking whether or not you should put credits or debits into a transaction state, the answer depends on the requirements of the application.