Is nikkor 70-200 vr good for low light?

Hi. I'm shooting now with Nikkor 85mm 1.4D and would like to know. Is 70-200 vr I any good in places like dark churches or dim banquet halls? I mean. I go sometimes as low as 1/30th or more shutter speed with f/1.4-2. Will I manage with aperture 2.8? I know that thousands of wedding pros shoot with this lens in just such conditions. But I'm not pro.

No zoom lenses are faster than f/2.8, so it is the fastest zoom lens you can buy. If you need faster, you have to go with prime lenses.

Your f/1.4 is 2 stops faster than a f/2.8.So if you are shooting at 1/30th with f/1.4, you have to go to 1/8th with the f/2.8, which would be unacceptably slow. In those conditions, you have no choice but to increase ISO. Say you are at ISO 200, you would have to go to ISO 800.

With some DSLRs ISO 800 means some noise. And that is where the high-dollar/full-frame DSLRs come into play as they do better at high ISOs.

And even with 1/30th, at 200mm you may have some camera shake, so a tripod/monopod would be recommended. True, the 70-200mm has VR so that might help a bit, but I have never been a fan of VR over a tripod.

I'm a prime girl, the majority of my wedding kit is no slower than F/2, with some as fast as F/1.2.
Churches are horrible places, like you, I've been in some where at F/1.4 I'd be shooting at ISO 6400 and 1/60.

I use, and love, the Canon 70-200mm F/2.8L IS, but not at weddings. It can be used outside of the church and it's great at receptions. It's a very versatile lens and although the VR is useful it won't replace a fast aperture.
For your next wedding, stop down your 85mm to F/2.8 and see what it's like for a few minutes. Check the RAW files after the wedding and see if they're usable (don't be afraid to bump your ISO) and then you can determine whether or not F/2.8 would work for you.
It would work amazingly well if you were willing to put a flash on your camera or set up remote strobes around the church but not many people like doing that (myself included). Most wedding photographers I see who shoot F/2.8 zooms typically use a flash. I would be more in favour of faster primes and that's really what I'd recommend for you.