I don't think it is. I think the faculty members know how important it is, and I always discuss funding openly with my supervisors from undergrad and grad schools. One of my lecturers once commented directly that US schools have more money and discouraged me from applying to UK schools ....
Also, I had a friend who spent a lot of time connecting with a Cambridge professor and he had a huge change getting in. I told him to ask about funding in the early stages and if they don't have money for him, just don't waste his time. He didn't really pay attention to it and it turned out he had to give up Cambridge, because, no, money. I would say that he wasted a lot of time and energy on the program that he couldn't afford.
So yes, ask it. I'm also working on the 24 phd applications and I only look for the unis that have funding available. Trust me, otherwise it would be a waste of time for you and the school.