Yoga is in religion. Religion is not in Yoga.
Classical yoga is not dogmatic about the inclusion or exclusion of God or the Divine in the practice. Indeed, most of the practices of yoga make no reference to this topic, one way or the other. The Divine finds a place in Yoga, not as a compulsion, but as an option.
Asanas & pranayama are basically moving & breathing with mindfulness in a way that helps promote the health of the individual. There is nothing intrinsically theistic or atheistic about them; they are just health practices.
The Yogasutras suggest devotion as one option within a yoga practice to keep the mind focused & peaceful. But there is no requirement in yoga that the person believe in a Divine entity, or adopt a theory or doctrine of divinity.
As yoga views it, belief in the Divine is one’s personal choice, but a steady & peaceful mind is essential for a balanced & successful life. The eight limbs of yoga as described in the Yoga Sutras of Patanjali is the means to a steady & peaceful mind. ~ AG Mohan