Steps to reproduce:
1. Create a VSTS project with a git repository
2. In VSTS project, create a Jenkins Service Hook
3. Create a pull request with an associated work item
4. Wait for the build to be triggered in Jenkins

Expected results:
The associated work item should appear in the UI of the build summary

Actual results:
The work item does not appear (see screenshot)

I also tried including the work item ID in the commit message (#1, in the screenshot below), but that did not have any effect.