If you have grass in your garden and you have water for your dog out there... it's not going to be an entirely bee free zone.
And I suspect sometimes they suffer some sort of mass killing (someone sprays a flowering fruit tree with pyrethrym during beeness hours) and then they turn up everywhere - crawling along the ground. ARGH.
My backyard lawn has flowers in it - pretty small ones (kikuyu and couch) but bees still go there. And clover is the pits. And we have a couple of flowering shrubs (rosemary and westringia), but as long as Frosty doesn't actually chase the bees and try to sniff them, they do a good of keeping clear. You just have to watch a flowering gum tree full of nectar birds and bees - to see how good the bees are at avoiding other nectar gatherers.