SkyPriority is just a set of benefits, most notable Priority check in, security and boarding, which is available to:

• Business class passengers
• Premium Economy passengers
• Passengers having booked through a corporate contract*
• Skyteam Elite+ status holders

Crucually Skyteam Elite+, as well as Business class passengers, receive additional benefits like Lounge access. This is not part of SkyPriority.

* Assuming SkyPriority access was included within that contract, this is not always the case.