“Is an alte bochor the equivalent of an old maid or spinster?”
Your question is unclear. Do you mean: Is an alte bochor the equivalent of an old maid or is it the equivalent to a spinster? (i.e. one as opposed to the other)
or
did you mean: Is an alte bochor the equivalent of an |old maid or spinster| thus lumping them together.
the nafka mina would be whether or not you consider an old maid equivalent to a spinster.