I understand that you are having issue with the Season Pass. Can you please let me know where you purchased the stand alone season pass? Was it from the In Game store, Console Home Store or Add On's menu, or from the PSN website? Can you also let me know what county you are from and what region you have your console set to? Can you please try uninstalling and reinstalling the game download? Have you double checked the Add On's list from the console home screen? Upon accessing the Add On's menu, select "View All" and you should be able to download your items there. You can also try remotely pushing the download from the website as outlined here: Download SEN Store Purchases to PS4.
Let us know if that helps!