Blueberry top hat in pot

Hey guys, I have 2 questions about my blueberries....

3 years ago I planted two tiny blueberry plants grown that year from seed by a friend (one in a pot and one in the boarder). The one in the boarder is not doing very well at all, so I am going to dig it up and give it to someone else. however, a lot of the info I have says we need 2 blueberries to pollinate the plants - is this true or will I be OK?

Also, the one in the pot was re-potted last year but I think it is getting a bit root bound - once it is done this year should I repot it again? I kind if need it to stay in the same size pot now, as I am running out of room on my decking!

Thanks in advance for the help :-)

 

I have just the one Blueberry and it is outside in a large pot. It has pollintaed ok and is covered in berries