How do star card upgrades apply to different varieties of the same vehicle?

There are star card upgrades that appear to be specific to abilities for just one or two varieties of a vehicle class. For example, the "Bomber Weapon Systems" card affects the Ion Cannon performance of the Bomber class. However, the TIE Bomber does not have the Ion Cannon ability (even though the card actually shows a TIE Bomber - see image below). Only Y-wings have this ability.

Does this card have any effect for vehicles of the same class which do not have the specific ability? If so, what does the ability do e.g. in the case of the TIE Bomber?

The cards will automatically update themselves to affect the ship that you're using.

Your example ("Bomber Weapon Systems") will affect "Ion Cannon Active Time" when you're using a Y-Wing (like your screenshot shows).

If you're using a TIE Bomber or a Hyena-Class Bomber, the exact same card will show that it affects "Missile Barrage Damage".