If you include White Balance settings in a preset applied to a Raw file, and apply that preset to a JPEG file, Lightroom tries to apply the equivalent white balance adjustment (but using the JPEG scale).  Therefore, the White Balance adjustment on a JPEG (using a preset based on a raw file) is necessarily an approximation.  We try to do the closest job we can, but results will vary somewhat on a case by case basis. 

The units of measurements displayed in the Basic panel (in Lightroom’s Develop module and in the Camera Raw dialog in Photoshop) for Temperature and Tint differ between RAW and JPEG files.  When working with a raw file, the Temperature slider ranges from 2,000 to 50,000 Kelvin and the Tint sliders range from -150 to 150.  When working with JPEG files (or other pixel based files such as PSD or TIFF) the Temperature and Tint sliders both range from -100 to 100. 

You might also notice that when working with RAW files, Lightroom displays a list of “preset” White Balance settings (Auto, Daylight, Cloudy, Tungsten etc. –  this list might differ slightly from camera to camera).  When you work with a JPEG file, LIghtroom only displays As Shot, Auto and Custom in the pull-down menu