As announced on May 24, the Bing Maps Developer portal shipped a new feature allowing you to restrict access on your Bing Maps API keys to a set of domains that you specify. Starting today, wildcard is now supported for referrer security whitelist setting.
For example, you can now do: contoso.com/* or http://www.contoso.com/*.
If you have questions or feedback for the team, please reach out to our Bing Maps Enterprise Support team at firstname.lastname@example.org.
– Bing Maps Team
Source: Bing Blog Feed