Many photographers batch process their images to save time, and this is one of the big advantages. Once you’ve photographed a wedding, you’re likely to have hundreds of images to edit, and batch processing groups of images can prevent you from wasting needless hours on individual tweaks.
Some photographers also like to have one style for a series of images, and this is much easier to do if you’re batch processing, as you can apply the same adjustment to large number of images. Individual editing obviously takes more time, but there’s more attention to detail with this approach.
Some photographers are happy to spend more time editing, making tweaks to individual images, and it does all come down to preference. Too many photos in the same tones or colours can get a little bit boring and predictable, so whatever you do, make sure you are mixing it up from time to time.