I'm not sure what cuddle cubes or bunk bed hammocks are but as for the vine felt is not a glider safe material. It would be better and safer to make it with fleece.
https://www.facebook.com/groups/suggiesewers/
if you guys are sewing the items this is a great group to ask questions and get patterns for non signature cage set pieces.
Also look on youtube there are some awesome tutorials for bonding bags and specialty pieces.