I ended up creating another instance of the same network printer using the smb protocol instead of ipp. Same physical printer, attached to the same box on the same network, using the same ppd file --but this time it works.
I read the Wine Official Documentation which implied that wine interacted on a pass through basis with CUPS. That's why I was surprised when my ipp network printer worked fine from Linux, but wouldn't work from wine running on Linux.
I still don't know why this hack worked. I've looked at various CUPS logs, but nothing stands out