Can I plant my Blueberries

Assuming that the cutting have rooted I cannot think why not. They are hardy.
Only question is has your allotment an acid soil?
Everytime I read of allotments people seem to be growing brassicas of one form or another and so adding lime. Blueberries will not grow in an alkaline soil, I think they sort of get by in a neutral soil but that is all.

Blueberries are deciduous shrubs so are dormant now; I would suggest that any convenient time between now and when they start to regrow in spring is fine. SG6 is correct, they must have acid soil or compost to flourish, so kel28 should certainly be repotting his/her plant this year in ericaceous compost, and also making sure that any added fertilizer is suitable for ericaceous plants (also use rainwater rather than tapwater for the same reason.)

It is also recommended that you grow more than 1 variety of blueberry together to improve pollination and therefore fruit-set; I have 3 different varieties which fruit well (keeping birds away from the berries is another matter!)