Implicating bound → restrained
Link to implication

Reason:

the wiki page for bound makes it pretty clear that restrained should apply in all cases with the following sentence:

This tag is used in all cases where a character is tied up, chained, cuffed, or otherwise restrained.

The restrained page lists rope as a possible means of restraint as well as "various devices" so I don't think there's any situation where a character could be bound but not restrained somehow.

Note that it shouldn't imply restraints because, while they are frequently co-present, the pose might hide them, e.g. behind clothing or the body of a character.

There is already an implication suggestion for fully_bound to restrained, this suggestion encompasses that one since fully_bound implies bound. Link to that post.

EDIT: The tag implication bound -> restrained (forum #252004) has been rejected by @NotMeNotYou.

not all bound characters are necessarily restrained. for example character with rope tied around their torso like this is bound but not restrained at all

I don't think that counts as bound, according to the tag wiki page for it. It's more like rope as clothing. As it's used now, it seems like it's unambiguously a restraint thing.

Snergal said:
I don't think that counts as bound, according to the tag wiki page for it. It's more like rope as clothing. As it's used now, it seems like it's unambiguously a restraint thing.

I am pretty sure that that was intended as a playful example, not a direct, exact 1:1 comparison.

The tag implication bound -> restrained (forum #252004) has been rejected by @NotMeNotYou.