In my experience, bare-rooted roses, planted now, are very unlikely to flower this year. You might just get one tiny bloom.
A rose bought in a container will usually be a more mature specimen. Climbing roses in containers in garden centres often have a growth of several feet. I'm not certain how much more growth they would make this season.
I'm not entirely convinced that all container roses are more mature. I've occasionally bought a rose (or even a fruit tree) in a container, and when I remove the plant from the container, most of the compost falls away. It gives the impression that a bare-rooted plant has simply been stuck in a pot of compost and sold as a container-grown plant.