Does anyone know if there's any pattern to the bonus points for adding an additional card holder?

[vardan22]

Does anyone know if there's any pattern to the bonus points for adding an additional card holder? Is this something we can get n no of points when we add someone to our account?

 

[Daver6]

The offer seems to come around at least once a year. I'm relying on my (shoddy) memory though. I'm sure someone has tracked the historical offers though.