Are codes account or system bound?

I have some humble wiiU keys and was wondering if I activated them on my nintendo account before the shutdown would I be able to download them if I ever got a wiiU (assuming nintendo hasn't shut down those servers as well) or are codes/purchases activated on the device?

Thank you for any help.

Edit: For anyone that comes to this later activating via web does not work if you haven't connected your account to a console. I put in a wiiU key and it returned an error but when I used a 3ds key from the same bundle it worked, so I guess nintendo knows I don't have a wiiU.