Attic moisture/ventilation problem?
1. no. existing vents are enough 2. much more likely is that you have a leak in the roof. It needs to be carefully checked from outside for damage and from the attic for missing knots or other access points
im a builder in uk ...come across this problem many times in your attic im sure you have insulation ..the insulation should stop at ceiling edge ..leaving the soffitts clearly seen ..never push insulation up to the rafters ...your bathroom should have an extractor fan ..and if any damp leave the door open when not in used
moisture can not make it to the attic...that is ridiculous..but if its moist in both places then both have exposed areas to the outside..