I wouldn't worry too much about adding additional yeast as long as you used a high gravity yeast and pitched a good healthy starter. You can add yeast if you want, but likely won't be necessary. The main consideration with a barleywine (or any high gravity beer) is making sure you check your final gravity a few times or a few days to make sure it is stable, and within the expected final gravity range for the beer. This way you can avoid bottle bombs. Other than that, calculate your priming sugar addition and bottle as normal.
By the way, I am also assuming that you plan to let your beer condition in the bottle for at least a couple of months. It will be necessary to carb it properly, and to allow the flavors to mellow out.