As SaveChanges, BulkSaveChanges already save all entities within an internal transaction. So by default, there is nothing to do.
However, if you start a transaction within Entity Framework, BulkSaveChanges will honor it and will use this transaction instead of creating an internal transaction.
Bulk Operations such as BulkInsert, BulkUpdate, BulkDelete doesn’t use a transaction by default. This is your responsibility to handle it.
If you start a transaction within Entity Framework, Bulk Operations will honor it.