tinyE: Am I to assume the widescreen patch only works for widescreen monitors? It doesn't add other tweeks that are nice for someone with just the traditional setup?
It only works for widescreen resolutions yes, it just expands the size of the map that's shown on the screen, instead of stretching it, basically the same as the widescreen patches for Baldur's Gate or Fallout. 1024x768 is the largest resolution Zeus does without the patch.
It uses the 1024x768 resolution in the game itself, so if you install the 1920x1080 version of the patch and then switch to 1024x768 in-game it actually goes to 1920x1080 (or whatever resolution you picked).
The Pharaoh patch works the same (same engine as Zeus)