Following up, as noted in the bug report (
https://bugzilla.redhat.com/show_bug.cgi?id=1860479 ) this doesn't appear to be oVirt
/ VDSM having issues. You can replicate the same inability to attach a bond to a bridge by
simply booting the 8.2.2004 installation media and trying a few manual 'ip'
commands. With older 8.1 or any 7.x install media, there's no problem, but starting
with 8.2, you can't attach a bond to a bridge anymore.
It looks like there may be some similar reports on bugzilla recently. I just wanted to
note here on the list that this isn't an oVirt problem, looks to be an issue with the
OS (kernel?).
Thanks again!
Mark