I should put out the disclaimer, I am a bartender myself. It was kind of her to give you the samples, especially if a manager/owner is watching her like a hawk, he likely would not allow that. I would guess her to the drop pour is also a management thing. Many managers feel that her method is the only way to do it; and the customer to customer consistency is their "it" factor. The reality though, is that most people generally don't tip just because you pour a stiff drink, they tip because you are a nice person, you are efficient, you make your customers comfortable. If she didn't hit those points for you, leave a buck, it's worth her time, and it's only about 10%. If she was stellar, tip more; but please understand that pour is often out of our control. You did the right thing by tipping her a buck, and my advice would be to get your Vino somewhere else next time, where the service can match or at least make up for the pour.