We didn't initially add a meter option for recycling light bulbs (lamps) because lamps aren't recycled in the same sense as an aluminum can, but they are separately managed so the mercury doesn’t end up in the landfill or being incinerated.
Even though it’s more about safe management, guidance to consumers often calls it "recycling" (https://www.epa.gov/cfl/recycling-and-disposal-after-cfl-burns-out).
We will consider adding this option (Recycled Lamps) in the future. Currently, anything that gets recycled contributes to your diversion rate. We're not sure lamps should be counted as diverted - because they are still disposed and not made into a new product. LEED for Existing Buildings focuses on the safe disposal of lamps. Their requirement is: “Hazardous Waste: Safe disposal of batteries and lamps (indoor and outdoor, hard-wired and portable fixtures),” and the credit excludes lamps in the diversion calculation.