There are many authors that have NO books that are posted on PBS.  Some of these authors have dozens of books, and i don't want to wish-list them all.  Is there a way to know if any book by a certain author gets posted?

The Wish List is tied to the ISBN, so no there really isn't a way to do what you want to do. You will have to pick which books are most appealing to you and get into those lines. If you have room, you can Wish List more than you think you would want, and then remove the rest when you get your fill.

Also remember, that just because a copy isn't immediately available here you may not have long to wait, most of the authors that I personally look for (when not immediately available) I will probably never get there books here, but I also look for books for another family member and when I've had to wait list for those I can watch the line get smaller every month.

Only you can judge what is or isn't worth waiting for.

It's fairly easy to wishlist multiple titles in a short amount of time.

Do a search by author, the titles come up on a new page, click on one title at a time, then add to wishlist.  Page back to titles, repeat.

The Wish List is tied to the ISBN

If a highly desired book is printed as a hardcover, trade paperback, mass market paperback, special edition, etc., each format is likely to have a different ISBN.  Therefore, if you really want a copy of a certain book and don't care about the format, you may want to wish list several ISBNs for a single title.

I realized that I forgot to add, that for older authors (with many pre-ISBN books) then the best method of watching for postings of their books is the saved searches.