Hi @cmg1986
Your question touched off some discussion within Percona regarding our state of IPv6 support in PXC - so thank you for that!! 
We have recognized it isn’t working 100% - my recommendation is to continue with your testing, along with having a look at this ticket and follow it, contribute if possible to the conversation:
https://jira.percona.com/browse/PXC-3767
Thanks for being an active member of the Percona forums!!