A few comments.

First, the Bible nowhere says that one shouldn't work on Sunday. It says that one shouldn't work on the Sabbath, and the relevant prohibition is contained in the Law given to Moses, which means that it referred originally to the Jewish Sabbath, Saturday.

Second, as Peter Fosl said, the view that the Bible is literally true, through and through, is largely a recent invention and would not be accepted by most people who call themselves Christians. But I'll agree with this much: Those who run around quoting Leviticus's prohibitions against homosexuality while eating pork have a lot of explaining to do. Indeed, those who ban gays from their churches while admitting those who are divorced have some explaining to do, too. (Jesus is not recorded ever to have mentioned homosexuality, but Matthew records him as having prohibited divorce, except on grounds of infidelity, on two separate occasions.) Those who "proof text" tend to be rather selective, as indeed they need to be, since the stories contained in the canon contain so many different perspectives, and those excluded (largely for political reasons), such as the Gospel of Thomas, contain yet more. The people who wrote these scriptures weren't hung up on literality the way people nowadays seem to be, and it seems pretty clear that they didn't take themselves to be giving any kind of final answer either.

Third, it's often helpful to understand something about the culture in which Jesus and the early Christians lived when trying to understand the scriptures. For example, it is arguable that in prohibiting a man from divorcing his wife except for marital infidelity, Jesus was trying to defend not the institution of marriage but the dignity of women. In Jesus's day, a woman who had been divorced was often a social outcast and usually had no independent means of support. (The same is true in many countries today and was true even in the West until not long ago.) A man who divorced a woman was thus often consigning her to poverty. (For much sensible and accessible reflection of this kind, see Peter Gomes's The Good Book.)

Fourth, the question what relevance the Law has for Christians has been debated since Christianity's earliest days. Perhaps the hottest issue among the early Christians was whether one could be a Christian without being (or becoming) a Jew. This debate is recorded in Acts and often referenced in the letters of Paul, who argued vehemently that the new faith should be open to those of all nations. (That's what Paul's talking about when he talks about circumcision.) Paul won that argument, in the end, rather decisively. His reasons for doing so are beautifully illustrated in Acts 10. Many Christians take this story to contain a profound argument against exclusion of women from ministry, of homosexuals from full inclusion in the church, and so on and so forth.

Finally, then: Does it really matter how faithful this story is to Peter's experience? Does it matter whether Peter ever had such an experience? Does it matter whether it was "just a dream"?