Roasting vegetables that have been cut on raw bacon board? Safe or not?
What do you mean by "raw" bacon? 
In a lot of with world bacon is only available cured and smoked -- in which case see this question (If you are unsure see that question also. There is some debate about this.).
The bacon itself is probably safe to eat without further cooking, and the peppers certainly.

On the other hand some people in some places (the British(?)) have this thing for unsmoked bacon which is basically just raw meat.
In which case you have contaminated the peppers.
But it doesn't matter because you are cooking them anyway.
And any contaminants are probably not going to have time to multiply, and produce non-heat destructed toxins between last night and when you cook them.
(If not you probably have other problems, like the bacon already being spoiled)