There have been many reports of people on Suboxone suffering from high blood pressure so I think we can assume it is not just a coincidence, although it is not reported as a side effect.
In fact the information I read said that there is a danger that people on this medication may suffer with low blood pressure (feeling dizzy when they stand etc)
This is a drug that needs to be respected and decreased slowly.
I also heard of someone who increased the dose and her high blood pressure regulated, so it really is a good idea to talk to your doctor, I wouldn't recommend changing dose without consulting him/her first.