I planted my hops next to the grape vines, gives the hops a good climb. I'm afraid they might choke the grape vines I already have. Can they grow together without problems ?
As I understand it hop vines are pretty vigorous (growing to be up to 3m tall in one season), so yes, I would worry about them choking out grapes (or at least competing for leaf space) if they were planted to use the same trellis. Of course, like most close plantings, they may work fine, just with somewhat lowered yields each.
You should try it for one season, and if there's too much competition, then just dig up the hop rhizomes at the end of the year and replant them somewhere else in the spring.