Sorry, but I've got to disagree with you. IMHO, there is no doubt that both images have been altered for publication. At minimum, the gray sky version has the added texture, text, etc, and from its overall look, I can almost guarantee you in a twilight cityscape such as this, the vivid version would have come out of the camera needing major color correction, major tonality adjustments, etc.
In addition to my claim that both experienced serious PS work, I am quite sure that the gray sky version is much closer to the original than the brightly colored version. The clearest evidence for this is that the JPG compression block artifacts are vastly worse in the vivid version compared to the gray sky version, especially in the smooth areas like the water. This increase in JPG artifacts is exactly what one sees when you crank up the vibrance, saturation and local contrast to add "zing" to an image. This is one of the major stumbling blocks when preparing images like the vivid version. In contrast, if you go the opposite direction and reduce the vibrance, saturation and local contrast in an image, yes, the JPG compression artifacts do become less prominent, but not to the extent that is seen here.
Tom M
(The JPG compression artifacts are much more evident if you click on both to see them at full resolution instead of just looking at the in-forum preview versions)