Google Places API: How to use multiple types?

If your are using in a query string, use the | separator. Remember that only 'geocode|establishment' is currently valid as a collection type, which is the same than not specifying any combined type.

See: https://developers.google.com/places/web-service/autocomplete#place_types

You may restrict results from a Place Autocomplete request to be of a certain type by passing a types parameter. The parameter specifies a type or a type collection, as listed in the supported types below. If nothing is specified, all types are returned. In general only a single type is allowed. The exception is that you can safely mix the geocode and establishment types, but note that this will have the same effect as specifying no types.

According to Google Documentation, point_of_interestis of type 2, which are not supported in the types filter of a place search, or in the types property when adding a place.