grammar - "Bear something in mind" or "Bear in mind something"

The natural phrase is "Bear X in mind", the other construction always a second choice.

The X is a direct object, and English prefers to put direct and indirect objects without prepositions before prepositional phrases: "Give John the book", but "Give the book to John".

On the other hand, we also do not like to put the parts of uncommon idioms too far apart.

This particular idiom tends to take phrases in 'that' or 'whether', which are hard to get out of cleanly. So we push those to the end, after the prepositional phrase that closes idioms of this form, to avoid confusion.

I would go with "Bear theorems [1] and [2] in mind" because it does not have this closing-a-phrase problem. But "Bear in mind that blah, blah blah."