Not necessarily. It depends on the rules of the programme to which you are crediting. BA should display them on their programme information. A convenient rough guide (though I find that the information is not always accurate) is wheretocredit.com.
For your future information, you mention the variable of who operates the flight. Often that is the same airline that markets it (but not always - think of a codeshare as an example) and that can also be a variable in some cases.