I have one of the Profile bottles. I can use it on my small (48 cm) tri bike with no bracket. I didn't even know there was a bracket.
The only bracket I have used is the one that came with my old JetStream years ago. I liked the old JetStream better than the Profile bottle. I have the sponge from the JetStream that I use as a "lid" in the Profile bottle. I just fit the bottle between my aerobars using the rubber bands. No problem. I love being able to sip away and remain in the aero position. I also love being able to pour water into the bottle during the race...and keep my water right up front. The only thing I don't like is the wind resistance it gives by being out in front. I especially don't like the wind resistance with a strong cross wiind.