Not consistent on adding a list from one private channel to another

Hi, 

I am trying to create a template using list. I want to be able to reeuse the template from one private channel to the next (still within the same team). 

I have access to create the list using existing list but my other member does not. They are also an owner and have full access to the private channels. 

Help this just seems so inconsistent we might as well go back to the spreadsheet!