Update - Fixed
Turns out the selection for Include only related values starting from "WorkOrders" needed to be selected. Checked that off and it worked properly.
Just wanted to make sure the solution was here in case anyone else had issues.
A good source of conditional value list examples can be found in "Adventures in FileMaking #1 - Conditional Value Lists"
This file demonstrates 8 different conditional value lists in its current release. A new release will soon up this to 10 different examples, the added two being value lists produced by scripts that are compatible with the Perform Script on Server step that is new in FileMaker 13.