Varnasrama dharma is the socio-religious path of material acquisition and moral law. There is practically no love of God in this path. It is a bargaining with God for material attainment.
Spiritual life on the other hand begins with moving away from such a path by following the socio-religious system but without attachment to the fruits of material acquisition. This is called (niskama) karma yoga.
Such detached action results in the ingress of knowledge. When knowledge is attained, one become exempt from the laws of dharma. But this does not mean the jnani engages in immoral acts. He or she has no desire for such and this lack of desire is the symptom of knowledge. In this sense the laws do not pertain to the jnani. The jnani conducts herself like a person in knowledge that is experiencing inner life and as such is not involved in the socio-religious world but rather the contemplative world.
However, the power of bhakti is greater than jnana. Thus mere faith in her efficacy that results in adopting the path of bhakti in all seriousness also exempts one from the system of varnasrama. Such a devotee is also a moral person but more so a spiritual one in ideal. Instead of performing five kinds of sacrifices before eating to avoid the karma involved in cooking and feeding oneself, the devotee merely offers food to Krsna and eats the remnants. Simple and better. And so it is with all of the rules of varnasrama.
The devotee as well as the jnani embrace the hygienic sensibilities of varnasrama and might follow the entire system in a culture where it is manifest (which does not exist on Earth at this time) to set an example for others or abide by such a societies rules, but to think that following or not following varnasrama will enhance or inhibit one’s bhakti is to be engaged in bhakti “covered by karma.”
Bhakti is an independent path. Varnasrama does not beget bhakti. However, because Visnu is worshiped in varnasrama (along with every other god and goddess), even without knowledge of who he is, it can be said in the most remote sense to be a factor in bringing one to vaidhi bhakti. But it can never be a factor in granting eligibility for raganuga bhakti, which is soley dependent upon mahat krpa.
The tension between morality and spirituality is an interesting subject. The extreme is presented in the Gita to underscore the difference. Arjuna, for moral reasons, does not want to fight. Krsna says fighting is moral as the dharma of a warrior. Arjuna replies yes, but in this war innocents will be killed. Krsna agrees and then says that nevertheless even killing, if it is done out of necessity in the context of pursuing spiritual life, bears no karmic reaction!
Baladeva Vidyabhusana explains in his commentary on Gita 2.35:
Arjuna: “You have explained by verse 38 and the verses following it, that I will attain sin by not fighting since I will be giving up my duty. But still, I should not fight because sin will arise from killing brahmanas and gurus in a war to gain a kingdom.”
Krsna: “It is not so: you will not incur sin by killing them, when you are fighting with the desire for liberation.” This is explained in this verse.
Later at the end of his discourse on yoga that begins with verse 2.38 and ends at the close of Chapter 6, Krsna again stresses spirituality over morality. In Chapter 6, Arjuna asks what will happen to him if he gives up the moral course of varnasrama and takes to yoga but fails to attain success in yoga. Krsna then reassures him as he does earlier in 2.40 that there will be no loss. He then says that if one imperfectly engages in yoga and does not attain complete success, that person attains the realm that moralists attain only by perfect execution of varnasrama dharma.
Furthermore, a moral lapse in karma yoga is a blemish and such a fault in jnana is a disqualification. But in bhakti a moral lapse is not a disqualifier, for the devotee is to be considered in light of his or her being properly situated in ideal, which in and of itself when embraced will generate the sadhana and mercy to right one in due course. And in the case of the gopi‘s parakiya, moral lapse becomes an ornament!