Q.Rhoeo
Is this plant suitable for around the pool? If so, what is a good companion? How should I prepare the garden bed?

Certified GKH Gardening Expert
Rhoeo needs well-drained, dry soil and can develop rot rot in wet soil, so make sure you can provide an appropriate site for it. A good companion would be any plant that also enjoys low moisture conditions. See this article:
https://www.gardeningknowhow.com/ornamental/flowers/rhoeo/growing-rhoeo-plants-in-the-garden.htm
The most important aspect of preparing the bed for Rhoeo is to improve the soil drainage if necessary:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-well-drained-garden-soil.htm
http://goodlifegarden.ucdavis.edu/blog/2011/08/how-to-improve-your-soil-drainage/