ワインはもう買ってある

Preparation

Explanation: Because –teある shows that a deliberate act has taken place, it is often used to show some kind of preparation has taken place, and is often used with もう.

Examples:

誕生日のプレゼントはもう買ってあります。

I’ve already bought her birthday present.

ホテルはもう予約してあります。

I’ve already booked the hotel.