Bloom doesn't actually address noise, but it can sort of hide it since it's a post effect applied over the top of the render (in most cases) and it kind of softens things.
How to best get rid of cloud noise depends on whether you're using v2 or v3 clouds. In this case I would probably recommend v2 if it's not very dense mist, it will render faster and results are similar to v3 at low densities and depths. In that case, with v2 clouds, the cloud Quality slider is going to be the main influence along with antialiasing if Defer Atmo is enabled. For v3 clouds I would actually first recommend increasing Voxel Scatter Quality in the GI settings for clouds, default is I think 100 now, but try 200 or even 400 to get rid of noise.
- Oshyan