It is considered good form to take a host/hostess gift whenever you attend a party in a private home. Obviously, there are exceptions, but even when it's not really expected it is almost always appreciated.
A bottle of wine is the most common gift. Many people misunderstand this tradition and think the gift is necessarily supposed to be used at that evening's festivities. It can be but it doesn't have to be. It is a gift and as soon as you hand it to your host/hostess it is their property and theirs to use as they see fit.
Don't be offended if they put it away and don't open it. Don't assume that means they don't like it. It may mean they like it very much and don't want to share it. That's their business and you should be okay with whatever they do. That's the etiquette rule. You can look it up.
Obviously, if it's a BYOB party or you have previously agreed to provide wine for the event, that's a different story, but a pure host/hostess gift is just that, a gift.
And it doesn't have to be wine. I've used flowers successfully. Candy or some other treat can be good, though it shouldn't be something perishable that seems to demand immediate consumption. Again, it's a gift. Your interest in it expires the moment you hand it over.
If wine is good, why not whiskey? I just heard from a correspondent who bought a case of Rittenhouse Rye Bottled-In-Bond (BIB) to make that his standard host/hostess gift. Buying a case brings the per-bottle price down to about $20. Rit is a nice choice because it's very good whiskey at any price, and happens to be a good value. In some markets, it's even a few bucks less. That price is here in Chicago.
Rittenhouse Rye BIB has been in short supply lately, but the drought seems to be over. I was in the Lincoln Park Binny's tonight and they had a floor stacking of about 50 cases, priced at $22.99 for the individual 750 ml bottle (less for a 12-bottle case).
Rittenhouse Rye is a straight rye whiskey. The BIB is 50% ABV. There is a 40% ABV version too, but that one is not widely distributed. The BIB is very popular with bars and cocktail enthusiasts. It is a Heaven Hill brand but the current product was made for them by Brown-Forman, before Heaven Hill increased capacity at its Louisville distillery. Now their rye is all made there, but it will be a few more years before that whiskey reaches market.