This question I just asked is just begging for it:
Done, I created the tag and added it to the question.
If by deep learning the OP meant "deep" neural networks, then the OP could simply use the neural network tag. Therefore, I don't see the point in having a new deep learning tag.
Since >99% of people using the deep learning mean "deep" neural networks, I'd suggest making the deep learning tag a synonym of neural networks, in order to avoid tag fragmentation.