Roses don't seem to do to well in pots. You should plant it in the ground in a nice sunny location.

Welcome to GoY
I assume these are the pots you bought them in. In which case yes they will flower this year but you must keep them well watered. they would be much better in the ground if you can get them in.

Which variety, though, Snowman? In my experience, some of the David Austin roses are shy to bloom after the first flush in spring, so these may have relatively few blooms the first year.
The way that I read the question is that you purchased them in pots, but are planning to plant them out.

Many thanks for the replies. They are now out of their pots and planted up in beds which had loads of horse poop dug in last autumn (about 12 inches deep of it!). They look really happy now and some are really taking off. There are a few very small buds so looks as if you're right, they will flower this year. They are Gertrude Jeykyll, Gentle Hermione & The Alnwick Rose planted up in a blue white and pink bed in semi shade with Aconitum, Campanulas, Fuschias, Cranesbill Geraniums and a sunny hot colour bed with the Crown Princess Margareta & Buttercup along with red hot poker and red orange and yellow perenniels and some blues with delphiniums, cmpaulas and globe thistles (delphiniums from Blackmore & Langdons not delivered yet).
The perenniels were mostly small plants from Macplants, no flowers just yet apart from dicentra spectablis, some clumps of Dr. Mules Aubretia and some delicate pink Geums.
Very pleased with the way they are settling in....been watering them every evening.