So, I agree with the consensus that you've probably done all you can if you don't want to spend any extra money. And as people pointed out, unfortunately people probably lie about honeymoons, anniversaries, etc. so it's not as meaningful as it should be.

My approach on special occasions is usually not to just ask for stuff for free and e-mail them that it's a special occasion, but to let them know about the special occasion in connection with booking and adding things that cost money, whether it's a nice restaurant reservation, champagne and chocolate in the room, flowers, spa treatment, etc. It may just be coincidence, but some of the best treatment I've received on trips is after doing things like this because I think it makes it clear that this is a very special occasion.

Even on non special occasions though; SPG has come through for me as a platinum guest way more times than not so I try not to worry about it as much anymore.