I was just typing up all the details you asked for and then realised my little "brain fart" :-)
The first selection was for template storage and not the container. The next screen offers "local-zfs" as expected.
I think it's time for a coffee...
I am making my first hooray into ZFS and as part of that wanted to create a LXC container (Debian+samba).
While setting up the container I only get to see "local", but not local-zfs. Was wondering if there is a technical reason for this? Should...