Hello Chitturi,
There are two forms of workbench request
1) Local Workbench request : In this case the workbench request has target system as <space>
2) Transportable workbench Request
This determination of Local / Transportable workbench request is based on package of the object and the transport route settings in the Transport Management System determine whether changes are recorded in a local or a transportable Workbench request.
So please check the package
Regards
Suresh Nair