Because at Bouvins, the English lost, and the French won. I guess in France it might be different.
Actually no.
Of course the English sources about HYW are so biased that is hilarous, but Azincourt is probably more known here.
Probably because of the same problem that made the Battle of Tours more known as the Battle of Tolosa : historiography.
Bouvines is the triumph of Capet dynasty, while Azincourt is the defeat of the Valois dynasty.
From a republican point-of-view, you have more interest of showing the latter, because it's why a king is bad, why nobility is bad for France.
Of course, since the XX, you have a great revival of Bouvines, but it wasn't always the case. I'm not saying Bouvines wasn't taught, it was just AS important than Agincourt, and had a less important mind in the common mind.
Maybe another reason, less based : i would think that french mind is more impressed and more marked by defeat than victory. Today, you have still books about Alesia, German occupation, but less continually and regularly than Bouvines, Crimean War, First World War, ...