I don't know how the coding would work, but it would basically be another thing at the top like others, you click it, a new page opens, you turn the wheel once a day if you are just normal user, more if you have that right thanks to fun tokens, and that's it? No need for email at all that way.
They send the links to wheel of fortune through email to encourage users to open their promotional emails. If they give the link to wheel of fortune on the website, that would defeat its purpose and many of users will probably disable promotional emails.