How is the central opposition in Pamela between the aristocracy and bourgeoisie?

Pamela's depiction of the relationship between the bourgeoisie and the aristocracy is packed with conflict. Pamela is a model of bourgeoisie virtue, opposed by the privileged and amoral Mr. B who feels he can use her as an erotic object because of the social gulf between them. However, bourgeoisie values win the day with Pamela's virtues impressing Mr. B, subsequently leading to his reform and their marriage.
In the marriage of Pamela and Mr. B, we see a two-way assimilation: Mr. B. becomes more sympathetic to the bourgeoisie value system and Pamela becomes a part of the aristocracy. Their marriage does not end all opposition, of course: Pamela must still learn how to become a lady and Mr. B's sister opposes the union. But in the end, the two worlds reconcile, with Pamela and Mr. B having what appears to be a successful marriage despite the class difference between them.