I just got past the 5k mark on SO, and at first it was very unclear where/how I could vote on tag wiki edits. I was expecting a new queue for these reviews, so I spent around 10 minutes looking in various places where I could do this but still no clue.
Then while doing some Suggested edits reviews, I stumbled on a post that was adding a lot of extra content to the original message, I was about to reject it as Invalid edit, until I noticed the little tag wiki line to the right of the title.
I think it's very confusing to have the tag wiki edit reviews in the same queue as regular edit reviews, because if you don't see that it's a tag wiki excerpt or tag wiki, it's typically edits that add content and should be rejected as *Invalid edit*s if they were on regular posts.
Also it's in my opinion you have to be in a very different mindset to review a tag wiki edit compared to a regular edit. Reviewing tag wiki edits is hard, this requires in case of not so well known tags to go out there and find information yourself and see if the edit corresponds. If I feel like doing tag wiki edits reviews I should be able to do as such without having to play the lottery in the "Suggested edits" to find one.
Why not put a separate queue for this? This would make it more clear what exactly you're reviewing, with no risk of confusion especially for users who just got this privilege like me. These are 2 very distinct tasks that require 2 different mindsets and so should not be mixed IMO.