Currently if you add a field in the fields parameter with a wildcard, no fields will be added to the hits layer. The situation is even worst if the wildcard matches the field name of the geo_point or geo_shape field, in that case a ClassCastException is thrown.
x-pack/plugin/vector-tile/src/main/java/org/elasticsearch/xpack/vectortile/rest/RestVectorTileAction.java
protected RestChannelConsumer prepareRequest(RestRequest restRequest, NodeClient client) throws IOException {
        
        final RestCancellableNodeClient cancellableNodeClient = new RestCancellableNodeClient(client, restRequest.getHttpChannel());
        final VectorTileRequest request = VectorTileRequest.parseRestRequest(restRequest);
        final SearchRequestBuilder searchRequestBuilder = searchRequestBuilder(cancellableNodeClient, request);
        return channel -> searchRequestBuilder.execute(new RestResponseListener<>(channel) {
            @Override
            public RestResponse buildResponse(SearchResponse searchResponse) throws Exception {
                try (BytesStream bytesOut = Streams.flushOnCloseStream(channel.bytesOutput())) {
                    
                    final VectorTile.Tile.Builder tileBuilder = VectorTile.Tile.newBuilder();
                    ensureOpen();
                    final SearchHit[] hits = searchResponse.getHits().getHits();
                    if (hits.length > 0) {
                        tileBuilder.addLayers(buildHitsLayer(hits, request));
                    }
                    ensureOpen();
                    final FeatureFactory featureFactory = new FeatureFactory(
                        request.getZ(),
                        request.getX(),
                        request.getY(),
                        request.getExtent(),
                        request.getBuffer()
                    );
                    final InternalGeoGrid<?> grid = searchResponse.getAggregations() != null
                        ? searchResponse.getAggregations().get(GRID_FIELD)
                        : null;
                    
                    if (grid != null && grid.getBuckets().size() > 0) {
                        tileBuilder.addLayers(buildAggsLayer(grid, request, featureFactory));