What I am trying to explain is, there should be no conflict between the two events.
Gacha bonus took place between 12/29 - 12/31 11:59PM PST.
The 20% bonus takes place between 1/1 - 1/31 11:59PM PST.
You should "technically" be able to get both bonuses, that is, if you want to. (I hope I am not wrong or I might indirectly screw someone over. >_>;;;;;;;;)