Has anyone heard of this wood being used in a bamboo backed bow?

Compression strong woods like osage, ipe or even yew are better options for boo backed bows. You could build a boo backed burr oak but unless you are very experienced you might not like the results.

It was a torges bow. I had just never heard off the wood and questioned how it would preform.

Burr oak would probably do fine as a self bow.

It's probably not much different then backing hickory with Boo.