Can bv spread? if so how and where and what would happen if it does? also can the antibiotics not work?

No spread: I think you're asking not whether BV can be spread to another person, but if it can infect other body areasin addition to the vagina. SThe answer is no; it is strictly a vaginal problem. However, women with BV are at elevated risk of pelvic inflammatory disease (PID, Fallopian tube infection), so get care immediately if you develop low abdominal pain.