Put them in larger pots. 3 to 5 gallon pots.

Kt

In addition to the fact that they need to be pe-potted into much larger pots, as kentuck pointed out, it may be at least a year before your bamboo put out any new growth. Bamboo growth characteristics are different from other plants. For one thing, existing culms do not get taller or bigger in diameter. You only get growth when new culms appear...usually in the late-spring.

If you bought Bambusa oldhamii (the most common 'Giant Clumping Bamboo') it will definitely get tall enough for you, but it make take a few seasons. I used to have mine in a pot...I kept potting up until I got to 24" diameter, and it was getting too big even for that. Now it's in the ground and on its way to getting huge.

Do I bring them in for the winter? I'm in zone 6.

I put them in bigger containers right after the first post here. Now I just watch them everyday to see if I see any new growth. I see a tiny little thing coming up next to the Blue Mountain. Keeping my fingers crossed.

ellenmarie-
Putting them in new pots will be unlikely to produce any significant new growth this year...but it will make the plants healthier. As far as bringing them in for the winter, you should do that because bamboo in pots are not as cold hardy as in the ground. Also, it would be good to know what the actual scientific names of the bamboo are. Blue Fountain" is probably Fargesia nitida, which could be planted out next year when it is more established and survive your Zone 6 winter (albeit with foliage/culm damage)...it's in-ground hardiness is about -15F to -20F. The "Giant Clumping" bamboo could be a number of varieties, probably of the Bambusa genus, but none of those will ever survive a winter in a pot or in the ground in your area. Most Bambusas typically can't survive below 20F. I'm in Zone 8 and have never had any of them make it more than 1-2 years where I live.

Here are the scientific names.
Giant Clumping Bamboo (Chusquea gigantea)
Blue Fountain Bamboo (Fargesia nitida)

I'm going to bring the pots in for the winter. I want to keep them in pots so I can have them on the deck.

That's helpful. Well, Ch. gigantea is much hardier than the Bambusas...but still only to about 0F. The main issue with this bamboo is that it can get large, will require pretty large pots in the future to stay healthy, and may be harder to move around at some point, unless you start dividing it when it gets big.

Wow, I've never heard Chusquea referred to as 'giant clumping bamboo'. Usually it's 'Chilean-something'.

The problem I have with growing bamboo in pots is the pot getting too hot and killing the roots. Shade the pots with wood, gravel, or put inside a decorative pot/planter.