Tag wiki's are unique from post edits in that they often are a lot more than a copy edit. Often, editors will pour a good chunk of time into a great tag wiki edit that adds paragraphs of excellent material and get two rep as a reward. However, if they wrote that same edit as an answer to a question, they could have gotten boatloads more rep.
I propose a tag wiki suggested edit bonus that can be awarded by reviewers from their own rep for an outstanding tag wiki edit.
The amount doesn't really matter as much as the recognition that, "hey, this is a great edit and is an exceptional example of a tag wiki edit."
Perhaps another qualification should be added to prevent abuse, such as X reviewers have to agree that the edit is deserving of it. Another idea is to award a badge (like [Good-Answer]) instead of rep that can be accumulated for X great tag wiki edits.
The manner of recognizing those outstanding edits is not as important as recognizing these edits and the individuals behind the scene who have put forth their time and effort to make Stack Exchange a better place.