I live in a mid sized city in North Carolina. Generally speaking, it lacks diversity. As a mid-sized city in the south, my community tends to be politically conservative, church-going (and predominantly Protestant/Baptist), and somewhat old-fashioned in terms of progression.
While it is difficult to define classes or categories of people who are treated as "subordinate" in general, I will attempt to give a couple of examples. I do not think my community is particularly open to homosexuality, generally, or giving marriage rights to anyone living in a non-traditional marriage situation. Though I would not consider racial minorities to be treated subordinately, certainly, there is much to be said for the number of white people who live in poverty compared to the number of black and hispanic people who do. It seems those with money tend to make the rules.
I also think non Christians are looked down upon in my community. I grew up in Washington State, where nobody asked a stranger, "Where do you go to church?" Here, it is one of the first questions people use to get to know one another. It is simply assumed that everyone goes to church.
Certainly, in a community that lacks diversity, there exists prejudices, social segregation to a degree, and inequality. But I'm not willing to consider any of these things as "subordination" of one group to another.