I think that existence of wonders like that is a fine idea.
For example, Cynosure is technically a godlike AI that requires priests-Operators with high cognitive abilities. It would've made sense if it boosted Science specialists.
Also it should be kept in mind that not only yields can be increased, but specialist's health and food consumption also could be manipulated (like Freedom perks in Civ5).
But I'm generally against idea that if A isn't good and B isn't good, then make A buff B is a way to go. Specialists have to be decent on their own, and wonders have to be decent on their own too, and if some wonders buff specialists further - well, even better, unless rushing it would become a no-brainer.
I wrote a balance suggestion on grower specialists some time ago, sadly it was mostly ignored. I suggest you to check it.
I think this is a good idea. The downside is that micromanaging specialists is not something that many players do, or enjoy doing (I am one of them). But I agree that wonders need to have better and clearer impact.
UI is at fault here. It could've been made much more convenient. The main idea - you don't have to care about which buildings got empty specialist slots, you only need to care about total amount of specialists available by type in a city, since the specialist yield doesn't change from building to building, only amount of specialists does; that's why technically a unified specialist UI could be made, without binding it to building list, which could've been absurdly cool and easier to use than managing tiles in a city. Or do you hate tile management too?
