Great question!

Even if you change your email address in your Design Home game, you can just use that new email address to log in to the VIP Program! You can access your VIP Program page using whichever email address you currently have linked to your Design Home account.

You may need to re-verify your email after linking a new email address in the game. This will also be the email address where you would receive your One Time Passcode to verify the email.