According to one legend he was descended from Brahma, the Creator and of Sati, the consort of Siva. Thus making him related to his sibling god of wisdom sacrifices.
Perhaps he was just a man who was a true yoga practitioner. Being tuned into the oneness of yoga , practicing regularly and with previous oral teachings he mapped out the yoga sutras in written text for future generations.
And so we have all grown to adore what we call "the seeds of yoga knowledge".
Divine blessing to you Patanjali whoever you were and wherever you where born means nothing to what your legend and teachings have become.