get on to vs get together

get on to

verb
  • Used other than figuratively or idiomatically: see get on, to. 

  • To contact (someone) in order to raise or discuss a certain matter. 

  • To progress to; to start working on. 

get together

verb
  • Used other than figuratively or idiomatically: see get, together. 

  • To start dating; to start being a couple. 

  • to agree 

  • to accumulate, to gather 

  • to meet, to gather together, to congregate 

How often have the words get on to and get together occurred in a corpus of books? (source: Google Ngram Viewer )