Here's the thing - punishments / dicipline needs to be done fairly.
So, have you ever broken anything during a tempertantrum and what punishment did you receive (and who punished you)?
Then say "Dad, we need to talk. When I did X you punished me. When I did Y you punished me. I'm your child too and it's not fair if you don't punish my brother in the same way. I also believe that if you don't punish him he'll only behave worse later and may get himself into trouble at school."
However, there is a "punishment window" - a time during which punishment is appropriate. You can't punish someone for something you found out a week ago. They need to be punished on the same day it is discovered that they did something wrong.
In other words, it's probably too late to punish your brother now.
Telling your mother at this point will only cause friction between your parents. Her hands are tied because your father knew and it was his responsibility to choose the appropriate punishment at the time.