You must have the VPSC electricity rate (with or without time restriction) and a contracted power equivalent to or below 10 kW in your usual residence, which is contracted through reference marketers. The Social Bonus cannot be benefitted through Lumisa.
You will need to fulfil certain requirements in order to be classified as a vulnerable customer (25% discount), severely vulnerable (40% discount), severely vulnerable customer at risk of social exclusion or vulnerable customer because of COVID-19 (25% discount) established in https://www.bonosocial.gob.es/#requisitos.
Source: Ministerio par ala transición ecológica y el reto demográfico; Secretaría de Estado de Energía https://www.bonosocial.gob.es/#requisitos/tabla