What is it you're expecting the vbs script to do? Looking at this, there isn't a way to determine what the .vbs has done, so unless you're logging something than it'll be hard to determine what is happening. The COM is a pain since it's marshaled across directly, so you can't do things like error handling using PHP without implementing all the necessary logic.
Not sure what vbs has the capability of doing, but you should start by adding a logging feature. You should be able to flag the run command as well to change the windowed mode (the 0 is hidden), but I'm not 100% sure if it'll remain open. To me it look like it needs a '5' as the option, which MS indicates would do:
Activates the window and displays it in its current size and position.
If it stays open and the vbs issues output, I'd expect it to show up in there.