WP_Query: how to search tags in addition to a custom post type?

Below is what I have so far for a custom rest endpoint (‘placesdb/v1/search?term=’) for a custom post type (place). This successfully returns all the places that have the search term in the title or content. However, I also want to return all the tags (tag archive pages) that match the search term (the same result as calling the non-custom ‘/wp/v2/tags?search=’). Is it possible to somehow add the tag results to the place results? I already successfully did the front-end approach of calling the places and tags endpoints separately via ajax, but I would rather get all the data in one swoop. Hence my attempt at making this custom endpoint.