i am guessing the bondo is a polyester resin, similar to what they may use in the body filler applications
epoxy will always give a better bond with wood than poly.
and wont really be that much more expensive, availability may be the key.
you can try any of the wooden boat building supplies, they have lots of proven wood friendly epoxies in laminating viscosity.
i like west systems, personally!
but many others too.