This is done for convenience reasons as the application assumes you might be entering multiple bottles of the same wine. In this situation, you simply click the save icon to save another bottle of the same wine.
A practical example: You have ordered a case (12 bottles) of 2009 Robert Mondavi Estate Reserve Cabernet Sauvignon. Initially, you enter in the wine information (Vintage, etc) and click the save button for the first bottle. For the next 11 bottles, you simply need to click the save icon again.