A bolt-on agreement signed this week will mean the EU and US do not disrupt trade before the new deal comes in.
The European Commission said the extra agreement meant the US would exclude European wines from its changes to certification and labelling laws for the 2005 harvest.
Under the original agreement, signed in September, the US agreed to propose to Congress that American producers should be barred from using 17 traditional European wine names, including Chianti, Champagne and Burgundy.
The EU, meanwhile, agreed to recognise certain US wine-making tactics such as adding wood shavings to help the wine's taste mature faster and adding water to lower the wine's alcohol content.
The deal, however, has fallen on largely sceptic ears in France, with the country's wine co-operatives' union calling the deal "unacceptable". It said there would be "no concrete changes" as wines already using protected EU names would be unaffected.
French agriculture minister Dominique Bussereau told winemakers last week that he knew the deal was not that great, but that it carried no economic risks for French vintners.
His words prompted the national confederation of Apellation Contrôlée (AOC) vintners to say that Bussereau had failed to re-assure French winemakers about the deal, and had in fact had the opposite effect.
The co-operatives' union has called on the EU to continue negotiations for a fairer deal, despite pushing for EU Council ministers to reject September's agreement.
A spokesperson for the Commission said another round of talks was set to begin after Christmas, although these would be more complicated because the issues are set to be discussed in more detail.
The Commission argues that European winemakers, faced with over-production and declining market shares, would significantly benefit from better access to the US, which spent €2bn importing Europe's wines in 2004.
"The US is our biggest market," said agriculture commissioner Mariann Fischer Boel. "This deal will remove the legal uncertainty which has hung over this trade for several years and benefit producers on both sides of the Atlantic."