Dharma vs. Religion
Bhakti is not the dogma or belief of a particular religion. Bhakti is more accurately defined using the Sanskrit word dharma.
Dharma means the inseparable quality that makes a thing what it is. A stone’s dharma is to be hard, water’s is to be wet, fire's to be hot, sugar’s to be sweet.
The living being’s dharma is Bhakti. We exist to exchange in reciprocal love with God and to serve Him with devotion. Any scripture of any religion that teaches that principle is promoting Bhakti.