Our client does not let information be sent offshore. This isn't a discussion as to whether this is good policy or not.
I am wondering if there's any way to set the server that you send Google Vision's API calls to. In the same way you can select which server you want in Google's Compute.
At this time Google Cloud Vision is a global product and you cannot set a specific region for data processing.
On the following link scroll down to Global Products.
Vision OCR offers regional support
Vision OCR multiregion support
AutoML Vision is limited to us-central1 only at this time.