Is there a way I can search the Tags for tags with no tag wiki created yet?
You can use the Stack Exchange Data Explorer for this (specifically the
Since I am so very helpful, I just wrote a query to do this: Most common tags with missing wiki/excerpt. Feel free to fork it to suit your needs. Note that since it is the Data Explorer, you're not accessing live data, but reasonably fresh for this type of query I should think.
I'm not a SQL master so it's probably inefficient, but it finishes on Stack Overflow, so yeah.
I did it
You can get close by googling for +"There is no tag wiki for this tag" +site:http://stackoverflow.com/tags.
Just to add somewhat to the current answers, the only way of currently doing this is, indeed the Data Explorer.
A while back I created a query to display those tags, without wikis or excerpts, that you might be able to complete. Just put in the name of a tag which you know something about and all the related tags without wikis will be displayed in descending order by the number of questions tagged with that tag.
One alternative way to find tags with no tag wiki is to visit the NEW tab on the tags page as indicated by @Bart in the comments.
This will give you the latest added tags and those often doesn't come yet with a wiki or excerpt.
As you see how many questions already have the tag you can judge how valuable an excerpt/wiki would be. As a bonus you spot misspelled tags (retag those questions so the misspelled tag gets removed at 03:00 UTC) or tags that either should be synonyms of existing tags or simply be replaced by a better tag.
No, there is no way to search Tags using any Tag criteria, though at some point they may add the ability to search in favorite tags (see comments here).