I' am afraid at your height you would get uncomfortable very quickly on the Bonneville. The seat to peg distance on a Bonneville is almost too small for me and I am much shorter than you. An America, or any other cruiser style bike with forward controls might be more comfortable, but cruisers do not always make good first bikes, in my opinion. They tend to by heavy and the raked out front end is not particularly cooperative with a new rider's clumsy steering inputs and braking.
My standard advice to anyone starting out on motorcycles is to find a used standard or dual sport type bike to learn on. You are probably going to get very cramped up on most standards, like the Bonneville.
Given your height and inexperience, I think your best choice as a first bike would be a dual sport with a small to medium displacement engine [200-500cc's]. Typically, dual sports have a much taller seat height and are light. I don't know what's available in your market, but something like a Suzuki DRZ400? Normally I wouldn't recommend that as a first bike, but you are so tall, it might work for you. The seat isn't very comfortable, though.
After you have gotten some experience, you might want to consider a Triumph Tiger or a similar bike with a taller seat height and foot to peg relationship. I know a gentleman who is a bit taller than you. He rides a Japanese cruiser of some sort, but has had the forward controls modified and moved forward a few inches. It works for him, but he looks really odd when he stands up over the bike. The seat seems to be at his knee level.

That style of bike really isn't a good choice for him, but that is what he likes and he makes it work.
Your height is really going to effect your choice of bikes I'm afraid, as you are much taller than the "average" rider that bikes are designed to accommodate. It may not be practical for you to get the bike that appeals to you the most.
Good luck and welcome.