Not really, but kind of, in an indirect way. Promotion up to Senior Airman is based on time. As long as you don't get in trouble, you'll automatically be promoted to Senior Airman after enough time in the Air Force. But after that, you have to take a test called WAPS. It's 100 questions about general Air Force knowledge, and 100 about your job. They also figure in your EPRs (yearly reviews), any medals you've won, the time you've been in the Air Force, and the time you've been in your current rank. All of that goes into a formula, and you are then given a score, say, 275. Then they look at how many people they want to promote in each career field, and they set a minimum score, say 260 for that career field. If your score is over 260, you get promoted. If it's under that, you don't. Some career fields have lower minimums than others, so it is effectively easier to get promoted in those fields. They are pretty close though, most are within a few points of each other, so it doesn't make a huge difference. Some career fields are "critically manned" as well, meaning they have trouble keeping people in those fields. They are allowed to promoted a small number more than other career fields in order to encourage people to stay in, so it is a little easier to make rank in those career fields as well.
But like I said, it is all pretty close, so ease of promotion should not be a factor in considering your job. Studying the material you are tested on will go a really long way towards helping you get promoted quickly. Most people don't take it seriously and don't study, and then don't get promoted.