Finally got around to testing this. It's present in DL, DA, and TA, and only affects Gravity Accelerators-all other trade goods work as advertised. When you trade it to the AI, they don't get the bonus. When the AI trades it to you, you don't get the bonus. Presumably, when one AI trades it to another, the AI that doesn't own it doesn't get the bonus, but this is much more difficult to set up.
Also, while I'm here, when you build Gravity Accelerators, you get the bonus, but it does not show up in the Stats & Graphs screen (applies to all versions as well).