huh) interesting way how to do a wire render
,, dont know but i do it with mental ray)
1. assign the renderer to mental ray
2. set up the scene
3. do a skylight there as a light source
4. turn on the material editor
5. change from standard to composite
6. the base material should be a simple color or any material which u want like white
7. the first material slot would be standard and the color change to which u want that your wire would be, check wire
8. turn on in mental ray render setup final gather
9. render )