You will have to do a refresh in the workflow to get this details, from the controller to the OCUM and then from OCUM to WFA cache so that the finder return it.
Other way I can think of is passing this vlan as a parameter from the command to the next command.
Below is the link to the community post where the command to do a on-demand refresh of OCUM and get the same into WFA.
Specifically, refer to the post by "sinhaa Jan 28, 2014 8:28 AM"
https://communities.netapp.com/message/124437#124437
Regards
adai