Currently, the Tagged pages for a tag that is a synonym is completely empty. There is no indication that tag has been added as a synonym for another master tag.
From an end user's perspective, there is a gap here. What will a new user to the site think if they encounter this? Will they be able to make the leap and find information listed under
Proposal: When searching for a tag that is set up as a synonym under the master, replace the tag with its master prior to executing the search and use the notification bar to let the user know that the synonym has been replaced with its master so that the user isn't confused why they ended up at the [c#] Info page instead of [csharp].