You need to use stencil in between your textures to have this effect.
Create your wire frame and color textures, save them in separate files. create a gradient file from black to white.
In textures panel, first select any of the color or wireframe, set its influence to color. then select gradient file, set its influence to color, check stencil and rgb to Intensity.
Now select your other texture.
your gradient file determines what will show from both textures. Total black will show top texture, white will show below one.
the easiest way is to render both views out separately and then mix them in compositing, you can then play around with the z-buffer (or just a black to white gradient) and multiply by splotchy texture to get something like in your picture.