Last I looked, the pet battle UI does not use action ID's nor secure templates. This may have change in this last patch, but I did not look. For me, the important part was being able to hide/show elements of my addon securely via the [petbattle] macro conditional, which does work.
My goal right now is to let the Blizzard implementation of the pet battle UI to be used when someone is using my action bar addon and not replace it. I was more concerned with a player getting into something like PVP combat while in a pet battle and being unable to re-assert action bars securely.
[possessbar] uses ID's 133+
[overridebar] uses ID's 157+ (though, I suspect there *may* be override bars that could also use ID's 133+)
And yes, [overridebar] works for that one quest with ID's 157+
