Domain Access with URL Alias - same content, but with different automated aliases
I believe this is exactly what the Domain Path module is for.

According to the module page:


  The Domain Path module allows the creation of separate path aliases per domain for nodes created using the Domain Access module.


However, it looks like this module provides the option per node, rather than offering different pathauto patterns which I think is what you want. There's a postponed request in the issue queue for pathauto integration that offers a partial patch, but it's offered as an anti-proof-of-concept, it seems.