Are questions regarding quasi-judicial bodies, such as arbitration, on-topic?
I would say yes, especially in light of laws like the FAA. I don't see any downsides to allowing the questions.
I believe that questions about QUASI-judicial bodies should be on topic.
There are three basic kinds of law; statutory law (legislatures), case law (courts), and administrative law (executive branch). The third group makes "law" even though it is less widely followed than the other two kinds of law.
Arbitration can be legally binding, so I would say it is definitely on topic.