Partially implemented from what is cited on the page.
“Ability to barter with NPCs. A character with Trading can reduce the amount he pays for goods from NPCs and increase the price for goods he sells to NPCs. For each point devoted to this skill, a character receives a 5% bonus on market prices. Trading is also useful in running businesses to maximum profit and minimise losses.
Used to determine whether an attempted arrest is successfully negotiated.”
I haven't heard about it increasing your income from income generating facilities. Unless this is seen as "running businesses" as cited in the trading rules.
Facility Income Rules: http://rules.swcombine.com/economy/economy/index.php?page=4