It took some time since at first because only the Rarity Carousel Boutique has been spotted. But now we've gathered enough info and because of that we now know the full line-up for the Rarity Friendship is Magic Collection.

Possible new Friendship is Magic Collection Sets have been listed on Amazon. No images yet but the listings themselves are very interesting. We will see characters like Aloe, Photo Finish, Rarity and Twilight with a Spa Chair. Perhaps this one will be themed around the "Green Isn't Your Color" episode. But there has also been a listings for a Scootaloo and Sweetie Belle Playset so it's unsure yet,. Also an interesting thing is that one listings is called "Aloe & La Ti Da Spa Playset" We all know Aloe but then there's "La Ti Da". By doing some research I figured out it's actually the name of the Spa Playset from the 3.5 Generation of MLP. So perhaps we will get a large playset of the Spa from the show.
But by judging the names of the listings I think we can confirm that these are from the FiM Collection. Now we just have to wait for more information. You can find the listings below.