To be accurate, the Spanish Colonial Revival Style in the US was modeled largely on the regions of southern Spain, specifically Andalusia. The style also drew somewhat less from other Mediterranean climates such as Southern Italy, and even the Moorish influence of North Africa. These locations were all quite warm and somewhat dry regions. When people use the term "Mediterranean Style" this is usually what they mean, though it is not very precise. Also, many homes built here in the US were not really very accurate in terms of the austere front facade as they were conforming to our bulding traditions in this way. In an interesting irony, it was the rural farm houses of Andalusia that became the model for some very high-style and expensive estates of the 20's and 30's. The links I provided are homes that fit this description, as would Pahonu.
The building style in Southern Spain had everything to do with climate. The red tile roofs and thick (12-24 inches) stucco covered white walls were great insulators. The courtyards provided shade from intense sun. The gardens too were reflective of the lack of moisture, and so focused on decorative tilework, fountains, and water channels, that recycled the water and kept the courtyards cool. This would be opposed to, say, a classic English garden with it's ornamental flowers and other plants that consume lots of water, or northern Italian gardens that focused on box-like hedges and statuary. The various garden styles of Europe is a whole subject unto itself, and in this area Pahonu is not very true to the style.
Check out these links.
http://en.wikipedia.org/wiki/Spanish_garden
http://en.wikipedia.org/wiki/Spanish_Co ... chitecture
As a side note, I live in a townhouse that was built on a newly created marina developed 40 or 50 years after the Spanish Colonial revival Style was popular. The surrounding neighborhoods were mostly developed in the 20's and 30's, so the architecture of our complex looks to the neighborhood for inspiration. Therefore, we have the tile roof, etc... It's just not the same, though. I'm not complaining. I feel very fortunate to live where I do, but newer construction always seems to lack the craftsmanship of these older styles. If you care to see it, I can attach a link to our community website.