I have definitely noticed bee action on the 'Hardy Evergreen' flowers and they love the chives too, so flowering alliums seem to be a thumbs up.
The shallots look like they may produce every shade from white through to purple. The buds are very ornamental and quite a range of sizes. The clumps are all different heights as well from 25 to 55 cm tall. The little short ones may not make much in the way of shallots, but could be a great flower for the front of the border.
Mind you, they are bolting because of our hideous weather.
Might not work in a more temperate place?
I do have some small witchhazels! They've survived being bitten down many times, but not large enough to flower still.
I agree that bees like other creatures had to know what they can or can't eat. I am always surprised at the good sense animals show, in knowing exactly what medicine they want from my garden. Their sense of what they needed is as good as ours, maybe better!