I've done quite a few of these over the years. If the instructions don't say anything about it, I say I am looking for a bottle for someone else. I'm not a wine expert so that opens the door for them to ask a lot of questions about who I am buying it for. Don't get so involved in the tasting that you forget to look for the wine tasting fees, wine prices, spittoon, etc. It's really easy to get caught up in the tasting and conversation. And I usually try to use the rest room as soon as I go in as it is easy to forget. Good luck and enjoy!
Also check their hours. They each have their own individual days open and hours of operation.