i'm not an expert on renenathera, but trying more and more vanda types outdoors in los angeles. i do have ren imschootiana, which has lived on my balcony for over a year now, and it is just in a basket with no medium at all. i spray it every morning almost, and water well twice a week in warm weather, once a week in cool weather. it is doing fine, and bloomed for me this spring. i fertilize weakly-weekly.
i don't know how well yours will do outside, it is a hybrid of two filipino species i think, and both are warm/hot growing and need a lot more humidity than mine. you should probably bring it inside in cooler weather this fall/winter. they need very bright light, but cannot handle much direct sun here. i would love to find more rens that can take our winter weather... imschootiana has the smallest flowers in the bunch, but it was so amazing when it flowered. i'd love to try one of the larger flowered ones like yours, but i would bring it inside in october probably. i also have some little ren tom thumb hybrids, but not flowering size, they have imschootiana in their parentage, so seem to do ok outside, but the larger one did lose some leaves from sunburn. btw - 'blue' vandas do well here outdoors.