Ok, this is what you must do in order to get the UC if you have a physical copy:
- Contact EA and ask them to register ANY of your LEGIT Sims 2 games to your Origin account:
http://help.ea.com/en/contact-us/
- After you found your game on the list select "Codes" as the topic and then type "I want to register my Sims 2 games in Origin" in the details box.
- You'll have to wait around 40-60 minutes before an Advisor talks to you.
- Tell them you want to register your Sims 2 game to your Origin account.
- If you're lucky they'll add to your Origin account the Ultimate Collection right away.
- if not then proceed to register your game and after it's done you should receive an e-mail telling you they'll add TS2 UC to your account because TS2 will lose tech support on July 22nd.
I'm in the same boat as you... only solution is to install Windows via Bootcamp, or your Mac might be able to handle it through a virtual machine. 
)
