Interesting. As ANA Platinum I got an e-mail offering me IHG Platinum. I honestly think ANA Platinum is way more valuable than IHG Platinum...
If you live in Japan you can now automatically apply for a credit card (Superflyers card) that will give you Star Alliance Gold as long as you keep the card. If you live in the USA, with ANA Platinum you can access United Club for free with someone even in national flights. Same for Europe. So I think you are lucky!