Rock solid clock pulse sync between Bitwig 4 & VCV 2 vst,
using the Expert Sleepers SW Sync plugin.
No midi involved.
Ofcourse you can use any other sync pulse generator or audio pulse track as sync source.
I prefer the ES - SW Sync plugin as it never failed me, and has some interesting parameters to tweak.
There is a much more elegant way as can be seen in the Ableton example where i used CV Tools.
Bitwig has the HW-Clock device built-in, unfortunately that built-in device can not pass its signal to the next device (or vst) in the chain.
If you see the benefit of this too in having the HW Clock enabled to pass its signal to the next device in chain, please let Bitwig support know about this.
And make it a feature request, the more people will do that, the sooner they might enable it, my request for this is already 2 years old so who knows 
Same method for:
Ableton 11
Cubase / Nuendo
Reason 11
Hope this helps, if you have any questions let me know.