Alcohol Etiquette

Highly suggest talking to the venue and bartender on this - they have more experience than anyone! They do this almost every weekend! Ask the pros, consider the advice given in here, and then take some deep breaths. You're doing your best to be polite and the bar is definitely not the MOST important thing about the day

Personally as a bartender that has done private events like this I would 1.) make sure everyone knows that it is limited and they are only alotted so many drinks that way you don't have someone going up and getting 5 drinks while as mentioned earlier someone else goes up for their first only to find out what was purchased is gone now. 2.) If you are offering a full bar with beer wine and liquor then On average most bars legally will only serve about three cases of wine ( 36 bottles total) to 100 guests. That is also based on an open bar for 5 hours ( these are numbers we use when we do private events). Assuming you only offer beer and wine I would gauge your crowd. (personally mine would be like 3/4 beer and 1/4 wine but you will know your guests best). But assume for number purposes you do 1/3 wine drinkers and 2/3 beer drinkers.

in my example:

200 guests/ 3 = 66.6 round up 1/3 = approx. 67 guests and remaining 2/3 would be 133

1 bottle of wine should get you ABOUT 5 glasses depending on the ounces poured

67 divided by 5 (number of glasses from each bottle) = approx 13.4 Bottles for all 67 guests (1/3 of guest count) to drink ONE glass of wine.

In this example to provide 1-2 drinks per person I'd get somewhere between 27-30 bottles (additional bottles would be added incase anyone who was drinking beer on the first round decided to go to wine for the second round).

Again this is just my two cents as a bartender that has done many private events.