"Biomedicine" isn't really a science as much as a name of a degree.
It doesn't make sense to say one is better or worse, they're just different. If you ask my opinion however, i will tell you science is marginally better.
Biomed (mostly) is a degree created by the university marketing departments for people who hope to get into med, etc. It is mainly the content of a science degree repackaged (i think everyone will acknowledge this).
There are a few important differences:
Biomed:
* A fair lot of your subjects are chosen for you, especially in the early days. Good if you cant decide for yourself or want someone else to plan your degree for you (i guess?). It's designed for you, instead of you designing it on your own (especially earlier in your degree). Your opinion on this may vary. It is slightly more intergrated this way though, which is a small bonus.
* A few additional subjects science kids cant take. Nothing important like physics or biology, probably really niche subjects.
* Prestige, if you care about such things. It reminds me of a joke i heard once around campus - "Biomed is the degree you choose if you want to study science and show off your ATAR".
Science:
* All your subjects (beyond a very small amount of compulsory subjects) are chosen by you. For example, you dont have to study physics if you dont want to, i think biomed it is a compulsory part of the course (?). Even if my example is wrong, the general principal is there, you get significantly more choice in a science degree.
* Room for non-science electives. I've studied astrobiology, philosophy, history, religious studies, politics and the list goes on. Within a Monash science degree, if structured right, you actually have enough points to also major in a non-science area (say Japanese). So, that gives you an indication the degree of freedom and wiggle room you have. They are starting to make their degrees slightly more structured over the years though (probably trying to match Melbourne).