You can see general information about the number of wishes granted within your account. Immediately after you have granted wishes, the history ("Previous Grants") of all wishes granted is displayed.
Detailed history is also displayed on Manage Requests by title page. You can click "Stats" in the upper-right-hand corner for a quick view of the numbers or click View History to view members who were granted access.
Then, you can see which members have accessed your title by having their Wish granted.