There is a wildcard tag that is (presently) described as applying to the text matching context. However, many Java generics questions are incorrectly tagged with this. I recently created a bounded-wildcard tag with appropriate description, and started to re-tag many (appropriate) questions with it.
However, I quickly realized that this will be a painful effort. If some administrator has the ability to search questions for the text "bounded wildcard" in a question and from each question about Java bounded wildcards, remove the "wildcard" tag and replace it with "bounded-wildcard". That would be great and would probably be 95-99% accurate. Even better, he or she could eyeball the questions themselves.
Also, it would be great if someone would rename the wildcard tag to wildcard-text and prevent the wildcard tag from being created.