No experience to share but wondering what are you intending to grow? Pollination only become relevant if you are growing fruiting plants.

Well, I am hoping to do veges like tomatoes and cucumber - kind of an oasis with some cutting flowers and herbs too! I do mason bees at ground level so I became curious as to whether they would hang around up there too. I will certainly try it but wanted to learn about other's experience/knowledge...btw, this is in the pacific northwest of the US.

Tomatoes are wind pollinated - no need for bees :-) And most cucurbits like cukes and squashes benefit from hand pollination anyway.