Jan:

From what I have read and my limited experience, pollination is not a serious concern. Good pollination may increase the berry size but you will get a crop with any other variety. I would choose additional varieties based on fruit quality and time of harvest. We do have blueberry experts from your area that post regularly. Hopefully they will chime in.

The Fruitnut

For Northern Highbush varieties (which is what Blueray is), pollination by another variery certainly isn't necessary. Some studies show a slight yield advantage (but only on a few varieties) while others show no yield advantage. I believe cross pollination is more "necessary" on Southern Highbush and Rabbiteye varieties. Any other blueberry variety will work well, so long as the bloom periods overlap.

My southern highbush varieties Southmoon, Santa Fe, and Star set every berry whether they are pollinated or not and at any temperature. Last yr was the first they had any pollination at all after two heavy crops. Last yr I had bumblebees in the greenhouse during part of the bloom. Berries were bigger than the previous two yrs. They were also less sweet. But berry size and flavor may reflect more water and more nitrogen fertilizer in the spring this past yr than the previous two yrs. I also ran the greenhouse cooler and the berries didn't sweeten up until I got the daytime high above 80F.

From what I've seen they set every berry even those that bloom mid winter. The Southmoon and Santa Fe are starting to bloom now. If they do like the past two yrs, they will bloom continuously from now until at least March. They set every berry all winter even when I'm trying to keep temperature between 37-54F for chilling.

The Fruitnut