Sales people are notorious for feeling like they just don't have control of their sales and growth. Every single day, you are selling 2 things, and it's not as small minded as the wine in your bag or the wine on program: It's your book and you. Think about that. You are selling you as a person and as a rep, and your book, the quality of the wines your represent, the company behind them and your knowledge about them.
You are in the customer service industry. There are a thousand boring and few inspirational books out there talking about excellent customer service. You shouldn't have to read them to know that every opportunity you have to help your customer is an opportunity to raise the value of your stock as a salesperson. The most beloved salespeople are the ones that will go above and beyond to act as a resource to their accounts regardless of whether or not it will directly result in an order. This definitely includes finding out who carries a competitor's product. Want to own a wine list? Throwing deals, smack talking and bullying is cruel mistress. There's no loyalty in that tact. If you want to own a wine list, you need to be the greatest, most honest, dependable resource for your account. This demonstrates that you place their success ahead of yours (you should). Everything else is just petty.
Selling your book is a little more nebulous. It's not just sampling (although this is part of it). You really need to go back to the beginning of your relationship with your employer. Did you choose the book because of the quality of the company? Quality of the wines? Hopefully both. If you believe in both, you should be proud. 3/4 of the reps out there work either for a crappy company, a crappy book or both. Being a distributor is difficult. There are a million details that need to happen correctly for your accounts to receive their order correctly each week. Every distributor makes small mistakes once in a while, it's impossible not to. In order for your account to love you and your book, you need to defend your employers inevitable mistakes up to a point. You also need to do your best to help your employer succeed at programs and projects, even if you don't agree. This will help your employers to improve your book and work environment. Don't air your laundry to your accounts either. They don't want to hear about commission rates or goals. Discussing these details with accounts is petty, and lowers your stock. You can't truly be successful if your account doesn't think your employer is successful. If you don't like the way things are going, give feedback to your boss. If they don't improve, update your resume.
As a sale rep, you are all at once a Promoter, P.R., delivery driver and E.R. Doctor. doing all of these tasks well will help you to make the most of every opportunity. If you place a priority on a) helping your account be successful b) helping your employer be successful-you will be successful.