If there is not an actual mobile app on the roadmap (and PLEASE let there be - PWA just does not do it - navigation is terrible). Can you at least consider an app that just does messaging and can perhaps pulls up booking info?
As you are rolling our more messaging features with AirBNB, SMS, and (hopefully soon) Vrbo, it would be helpful. Much of our interaction is actually messaging, in some way or another.
The only thing that a true app can do that our responsive website can't, is alerts on your smartphone.
And, Google has announced that they plan to add that capability to Chrome browser. So that would be a far easier solution to the need. No ETA on this of course, but hopefully they'll actually do that.