Why do all drinks have to go through 1 bartender for many waitresses,usually have to wait at the table for drinks?

A strawberry lemonade is a bar drink?

Each person is trained in their position. Often times employees are not cross trained. Also, every person don't order bar drinks typically the bartender should have a handle... busy when business is heavy enough they call in for reinforcements

Maybe the waitress can't throw the bottle up in the air and catch it behind their back and pour you a drink without dropping the bottle because liquor costs money

Not sure... I know what you mean though... Maybe because their bartenders are certified and trained but their waiters/waitresses arent? That's usually the case with other grill places...