PCB conductor spacing high voltage
In cases such as this you should probably plan for worst case, which is two uncoated conductors. According to IPC-2221B, with a 200V supply (assuming 200V peak, as in 200V DC or 200V pk AC) you must have a clearance between two uncoated conductors of at least 1.25 millimeters. This is the number I would use for the design, even though you theoretically could get by with a little bit less. This just provides a bit of safety margin, which is especially important because you don't know where the line is between coated and uncoated.

If you don't have enough room for this sort of clearance, I would suggest rearranging your board. I wouldn't trust a clearance of any less, and you really need to make it work, no matter what. Consider running high voltage traces on an internal layer or on the underside.