The bad winter weather we have suffered this year has scorched and killed many shrubs, bay trees included. However in my experience bays are very resilient and invariably grow back. Nevertheless if you cut it back either during or just before a spell of frost you probably have done it a mischief. One good thing, you won't have to wait long to find out.
I wouldn't recommend growing a bay in a pot for long, they have strong prolific roots so they need potting on regularly, even large tubs won't hold them for long.