Are the options grants as transparent (internally) as the cash?

There is effectively no difference internally than externally here. There’s no like, big list of who exactly has what amount of equity. Of course, talking about compensation with your coworkers is a legally protected activity, and I have discussed the topic with coworkers before.

Personally, I don’t really care how much equity my co-workers have.

This implies that the goal of compensation transparency is to satisfy people's curiosity. I don't think that's the case. Regardless of how it's denominated, I think the goal of compensation transparency is ... uh... equity... no pun intended.