I have a three bushes, but I sadly know nothing about the specific varieties. I planted two new ones in a raised bed this spring and they are thriving (these depend on me for water b/c they are just outside the reach of the sprinkler system). I had one in the same general location in a pot that froze this winter and never came back. Interestingly, on the North side of our house in the bed near the front door, I have a bush that I grew from a clipping off of the deceased bush before it bit the dust. It has withstood several freezes and it gets regular watering from our sprinkler system. So, basically, my rough data points are this: In zone 7b, rosemary of unspecified variety has the best chance of survival when planted in the ground with plenty of light (indirect Northern or direct Southern), regular-ish watering (good drainage is key), and moderate shelter from wind and freezing during the winter.
I do remember this about that successful cutting--during its first winter in the ground, I placed a plastic bucket over it on the nights when we expected a freeze. Our last two winters have been mild with temperatures dropping below freezing only a couple of times.
My mother has a rosemary bush that seems indestructable. It, too, is situated near a brick wall which provides a bit of shelter from wind and elements. It's located on the west side of her house. I don't think she's ever done anything special to protect it from freeze. This bush and the parent of my oldest successful bush came from Blue Moon Gardens in Chandler, TX. My two new ones came from Walmart. We'll see how they hold up this year.
I'm afraid I didn't really answer your question, but maybe that "annual" rosemary will do fine over the winter with a little shelter?
