If anything, post-Napoleonic war between France and Britain seems less likely ITTL than it did IOTL.
That said, I can't see a German/French/British alliance lasting forever. Someone is going to have to be on the outs.
For my money I would see the French falling out. Germany is still pretty new at being a national state and aren't competition for the British, since they lack colonies at this time. With things in Europe quieting down I would see the French starting to look outside of Europe again. Colonies, trade, and resources are going to be sought after. With such a big colony (Australia) they will want to extend their power to protect it. The Russians, Austrians, and Prussians are not out of the game, they are justed taking a breather.
I could see Russia, Austria, and Prussia eventually going after the Ottomans. The Prussians and Austrians would want African colonies to compete with the British, French, and Dutch. Maybe the Greeks enter into this alliance to get the Ottomans off their back. Would the French, British, and Germans come to the Ottomans defense like similar nations did OTL during the Crimean War? With the addition of Prussia, Austria, and possibly the Greeks; the other European powers may not want a repeat of the Liberal War. Depending on when and if this did occur the French may side with them to gobble up Ottoman North African territory (or not join but move into the territory as a "protective intitative".).