I'd prefer a high quality pair of speakers and a sub. I have the Definitive Technology Inclines and use my Infinity 8" home theater sub with them. It sounds... epic. Playing BF4 in a small room makes it sound like WW3 has started. My speakers have a dedicated line out for the sub; by comparison, I don't think your Bose ones have one and thus you're going to be limited for hearing the full range of sound you may expect.
That is not to say that you couldn't get excellent sound from a bar, mind you. It's all about your space and/or layout.