I have vermetids and bumblebee snails in my 100g. I've had both for a while.
About a year ago, I did a big manual removal campaign on the vermetids and got everything I could see. Now I usually have about 5 or 6 of them somewhere that I eventually manually get and then I get 5 or 6 more. They're not really that bad if you keep them under control. I'd say once every two weeks or so, I go at the visible ones with needle nose pliers.
I haven't noticed the bumblebee snails doing anything bad, but Im not sure if they're doing anything to mitigate the vermetid snails. It doesn't seem possible that they could successfully attack an adult vermetid. Although, if I recall correctly, juvenile vermetids are small and move around, then plant themselves somewhere and start growing the tube. Maybe the bumblebees are eating them when they're in the mobile phase. (I'd love to hear all of this confirmed or denied, I'm just repeated what I've read somewhere about the lifecycle of vermetids)
Edited to add: I just did some google searching and found an article that confirms the above about vermetid snails
here.