(This is generic advice for increasing nitrogen -- I don't know much about hops specifically.)
Yes, a feeding of compost tea is an ok way to add nitrogen. The actual amount of nitrogen you will add depends on what went into the compost.
A better amendment for a quick nitrogen boost (don't overdo it!) is blood meal. Sprinkle some on the soil around the plants, and then water to let it soak in.
This is a temporary fix, the nitrogen will either get used up, or it will leach deep into the soil, or even volatilize into the air over time. So you may want to repeat this -- with small amounts -- every couple of weeks. A longer term fix would be to put an inch or so of composted manure around the plants; this will provide a source of slow-release nitrogen that will feed the plants over time. Repeat the application in the spring.