<p>Does anyone have any T4 example Templates (or links to same) that can be used to generate a Webservice?</p>

<p>I'm thinking of the fact that I guess the Webservice is not just the Vb or Cs field but also requires an appropriate asmx file.</p>

<p>I'm really not sure how to achieve this</p>

Oleg Sych: How to generate multiple outputs from single T4 template
; create another method that generates your asmx - should be pretty simple, as it's one line - and renders it to a file.
T4 Toolbox
also has some methods that are helpful for this.  Oleg Sych's site also has other articles that will guide you through it, particularly these:
T4 Toolbox
Creating a complex code generator