Hi Olivia,
Great question! The Health Service Type reference set grows each release as @Skerruish collaborates with Healthpoint and others who expand the list to match the offerings provided in New Zealand.
Currently HPI facility and organisation identifiers are not linking to the Health Service Type reference set - it is definitely something that could be looked into (noting that there would often be several services provided by one facility). As always use cases drive a lot of development effort, so if you had a use case in mind this would really help. @samburchell of Healthpoint has used the SNOMED health service types to provide groupings to enable searching by the service you are after to identify the providers of the service. The powerpoint from a previous SNOMED NZ Hui goes into more detail of how they’ve used it to enhance their product and serve consumers well.
Another approach I know of is using the health service type reference set to harmonise HL7 messaging from Districts, where local codes from the PAS are mapped to SNOMED service types (which is a nod to all the work @TaniaS did on TMT rCP)