Alaska Airlines Mileage Plan - Does AS get CC data from BofA ...

when we buy another airline's ticket using our AS Visa?

Just curious if/how they track our purchases and FOP. When we buy an AS ticket with any credit card, AS can identify the FOP bank, should it choose to track same.

Look at the T's&C's of the credit card agreement - it will state who BofA can share data with. Generally, individual data on credit cannot be shared with a 3rd party for other than credit bureau reporting purposes; they could share aggregate data on where AS VISA cards are used though.