Checking Tag of Trigger Prefab

I have a ball which I would like to pass through two triggers.

For the first trigger I have the script placed on the ball, which will add a counter to the ball as well as mark it for respawning at the top of the screen.

The second trigger will make instantiate copy of this ball.

I would like to write an if statement to check which trigger is which by using the tags, but I am unable to figure this out.

My best guess/google result is so far incorrect, it only works for the ball's tag and not the trigger's tag (linetag).

     void OnTriggerEnter2D(Collider2D twoPointBalls)
     {
         if (gameObject.tag == "linetag") 
         {
             //do stuff
         }

How can I check the tag (on a prefab) of a Trigger?