Why the Extra Life rewards like Helper's Halo, Glimmer Wings, Caregiver's Chroma Pack, Sparkle Trail and Patron's Plumage cannot be putted in the League Bank? It always says: The interesting thing is that none of the items have Cannot be Trade sign but you can't put them there!
As the others said, they are account bound. Another thing that cannot be put in the league bank are any items that are platform bound, even if they ARE tradable. I'd guess that's so you can't sneak them from a PC leaguemate to a PS4 one via the bank. Not that I've tried that....