The description says it is Zodiac and Air, the breeding instructions say to breed black and yellow. You seem to have to have black and yellow , but some have been getting it faster with black ,yellow and Zodiac. After I don't know how many fails with just black and yellow I switched and used Libra and Twin star. Got it the first time.
I agree that having the habitats fit together in such a way would be visually appealing. The only downside would be: with expansions taking so long it would months before I could actually have the room for it! It is a neat idea though.
As for the newest zodiac to the bunch, I've had no luck Neo Taurus despite trying several different combos both with and without zodiac involved. It's no surprise since I haven't been able to breed a single one of the new zodiacs but still disheartening.