Haven't studied social work personally but am in the allied health field and know of people studying both courses. Have heard great things about both courses but I think the person I know at RMIT seems more satisfied with their course.
The Monash social work students say it's an intense course (being a masters and over a shorter period of time), and haven't super enjoyed the structure of really long placements (I think they're like 14 weeks) and being heavy on assignments.
IMO if you know the field you want to go into, you might as well get straight into it with the bachelors (plus studying psych on the side would be really helpful).
At the end of the day, both are accredited courses so you'll end up being an accredited practitioner regardless of which uni you go to
I would suggest doing open days (idk if these are in person or virtual atm) this year to get an understanding of the vibes of the unis you're considering too!