Essentially, the primary benefit of studying a double degree is to broaden your career prospects, that is, gain the knowledge and skills required to work in the field of each degree, which is intended to give you access to employment opportunities in either field (resulting in more opportunities). However, this does not necessarily suggest that there will be a beneficial connection between both degrees. For instance, if a student were to study a Bachelor of Business/Commerce majoring in Human Resource Management and a Bachelor of Arts majoring in Philosophy, the student will likely end up working in either HR or Philosophy (the latter possibly involving a career in research/academia), given the significant difference in each specialisation. Based on this, it is important to consider your career aspirations, i.e. what kind of work are you planning/hoping to do once you graduate from university?
Having had a look at your other thread, you should consider the advice that was provided to you if you wish to work in the healthcare industry, including whether there are numerous employment opportunities within bioinformatics and the extent to which the Bachelor of Advanced Science (Honours) component can support you in terms of expanding the knowledge and skills acquired throughout the Computer Science component as well as its relevance to this field.
Another combination, such as a Bachelor of Engineering (Honours)/Computer Science (as you mentioned) is likely to provide an interconnection, given that it would be reasonable to assume that engineering and computer science have shared aspects. Knowledge and skills gained by studying this double degree program can therefore potentially give you access to employment opportunities that emphasise aspects relevant to both qualifications. Of course, it is important to stress your own career aspirations when attempting to make a decision.
I hope this helps!
