Appearently the transport of wine has been bothering people for ages, because I happen to own something like this:


Mine takes 3 bottles, also taller ones, and it's made out of thin wood and hard leather that protects them well. The leather straps are for securing the lid, generally not to attach them to a bike but who knows they might exist. There are also modern ones, and I don't know what you use right now, but if its a hard case I would use it together with something like this on the rack:

To keep it upright against the saddle or maybe use two of them, opposed, and secure it with a luggage spider. If it's tight it will stay upright.

But come to think of it, the solution is probably not in the bike but in the bag/case you use for the wine. If you have a hard case for the bottles or a bag with sufficient stifness and padding you can just attach two hooks to it and hang it from the handlebars or side of the rack or put hooks on the bike that fit the handles.