Sound bars sell because they are cheap & they fit a lifestyle application. They work using phasing tricks or the fancy DSP chips which fool your ears. Think of them like a cheap body kit to make your Accord look like a Ferrari . . .
On the subject of wireless speakers . . . the floodgates will open in the next 2 - 3 years. Wait.
fwiw . . . here is one of DTS's lab rooms. DTS (and Dolby) encode the sound on DVDs & BluRays. This is only a 7.1 installation as shown but note the rails on the ceiling. They can position any number of speakers in any position.
Ian