I've read up on the treaty of Versailles, and haven't found anything on whether or not the post war government of Germany renounced its claim to be Alsace Lorraine.
Part 3 section V covers the Alsace-Lorraine, the answer to your specific question is in article 51
The territories which were ceded to Germany in accordance with the Preliminaries of Peace signed at Versailles on 26 February 1871, and the Treaty of Frankfort of 10 May 1871, are restored to French sovereignty as from the date of the Armistice of 11 November 1918. The provisions of the Treaties establishing the delimitation of the frontiers before 1871 shall be restored.
The whole treaty has been transcribed to wiki so here is a link to section V
http://en.wikisource.org/wiki/Treaty_of_Versailles/Part_III#Section_V._Alsace-Lorraine