I have the opposite problem... When I used to have to play in a bar, especially some of the tiny hellholes with obstacles around the table, I'd get so focused on the balls I wouldn't even notice other people/objects, I'd just go from shot to shot walking right over people without noticing, sticking my butt on people's drinks at their tables before they had a chance to get out of my way. I have good pool room etiquette, I don't accidentally shark people on the table next to me, but in a bar for whatever reason (probably because it's dark and noisy and the table is the only thing lit well.. and the table has such buckets for pockets I don't have to take any time at all thinking about shots) I forget about the rest of the world.
I don't know that you need to practice pool in bars, but maybe spend more time in them when you're not playing pool, go sit in a noisy bar and do a crossword. As for the people walking around, I don't know. Maybe because it's I lived a block from Times Square for years, but a huge crowd of people bumping into me doesn't phase me at all. Just learn to go with it.
Bar tables are actually not all that easy to get position on for things like 8-ball, just because of size they can get crowded. Well-used bar tables often will not roll perfectly true and the rails are often mismatches, each rail on the table may respond a little differently (many of them rebounding very dead).
Depending on the level your game is at right now, practicing (with a skilled partner) on a bar table just to get used to the different positional strategy may be worth your time, but if you're still new-ish to pool I would stay on 9-footers for practice so you are a little quicker to identify bad habits, you can get away with sloppy form on bar tables and it will be hard to fix later. Straight pool is decent practice for the more crowded conditions you'll face on a bar table, playing a lot of short shots and moving carefully over short distances.