From Webkinz Insider Wiki
How to Get Wish Tokens
You can get Wish Tokens in a variety of ways. When it's your birthday, one is sent to you through KinzPost. You can also get Wish Tokens by winning them from the Wheel of Wishes and by playing Token Balloon Dartz if it's in the Daily Activities.
What do I do with the Wish Tokens if I recieve them?
What They Do
Once you get 10 tokens, you are able to see the Exclusive Items that are available to purchase in the Wish Machine. Exclusive Items can be purchased with different amounts of Wish Tokens. Items that you are able to purchase will have a background of blue and items that you need more tokens for are red.