In 2004 in the SDK it provided you the schema, but in 2006 there are documents about what is in the binding file:

and even how you can command line work with it here:

But no schema out of the box!

I needed the schema so I can take an existing excel spreadsheet of trading partners and create a binding file that will import all of them at once. I asked the product group how to extract the binding file, and was not given the information (having access to the product group with the MVP status has its limitations obviously), but I found out through some other friends. The command to produce the schema that represents the binding file is:

xsd.exe “C:\Program Files\Microsoft BizTalk Server 2006\Microsoft.BizTalk.Deployment.dll” /type:BindingInfo