Nugget rightly said "When creationism has been subjected to scrutiny and therories tested then it could be discussed in science otherwise it is a religious topic only."
So, it comes down to being "opinion" as do all matters religious.
But as a very small minority only subscribe to full rabid Creationism i.e Young Earth, Evolution is false etc etc I really do not think any more time should be spent on this, even in a religious Instruction class or allied subject, than say the Cargo Worshippers of the South Seas, or similar wacky ideas.
As to ideas like is there a Supreme Being etc these of course can be, and should be discussed as part of discusssions on Belief, but again, a good education will give both, or all, sides of the argument.
Creationism in any form does not form a counter-point to Science.