I'm a one or two bowl a day pipe smoker, so I haven't given this much thought. When they were kittens, our two Maine Coon lookalike rescue cats were fascinated with the pipe smoke, and they still seem to enjoy watching the smoke rise.
Cats are nose breathers, only breathing through their mouths when in distress. (The reason I prefer cats not overbred with short pug noses.) They are breathing through narrow passages, and they don't cough, sneeze, or leave the room, which indicates to me that they are not bothered by a limited amount of smoke.
Their sense of smell is more acute than humans', so they may be getting a lot more out of my blends than I am, flavor wise. They would appreciate the breadth of flavor discernment in jiminks' reviews. I think dogs would read an even wider range of flavors.