There are basically three options:
1) Proprietary adapter
Expensive, not available, still may not work well.
2) Use a flexible coupler outside both pipe and hose
Works, but looks a little unfinished
3) Make an adapter yourself
Use a hot air gun and concrete mold
Here's a not so quick video of the process.
1) anchor bolt to scrap wood
2) Make a cone shaped mold out of a PET soda bottle and some tape.
3) put mold on top of bolt and fill mold with concrete.
4) wait for concrete to harden completely (several days)
5) remove plastic mold.
6) Use heat gun to soften PVC
7) stretch PVC over concrete mold and allow to cool.