Graph-Document-Recommendations
Why not using a Multi-Model DBMS like OrientDB (I'm the author) or any others? In this way, with just one system you can store documents and graphs together.

It would be:
- much faster (because you avoid the double call to 2 systems where most of the times the 2nd call needs the output of the 1st call, so you pay a lot of latency)
- easier to manage: one DBMS, one set of skills, in the case of commercial support, only one vendor

Following your use case, with a Multi-Model DBMS like OrientDB, you could start with a FULL-TEXT query (the underlying technology is Lucene, the same of Elastic Search) and then navigate the resulting graph.

Look at the Social Travel Agency example about how you can mix multiple models at the same time: https://orientdb.com/docs/3.0.x/gettingstarted/demodb/DemoDB-DataModel.html.