Pure bandwidth is not the most important factor.
First of all you want to receive updates from the pool as fast as possible and send your shares as fast as possible to avoid stale ones. For this, the latency and physical proximity to the pool is more important. Just try to ping it and see how it behaves.
The good news is that your hashrate doesn't matter mostly, as the pool will adjust the difficulty so you don't send too many shares fast at once. But the number of miners matters. If you have 5 of them each is going to be getting a different job and each will be submitting his share. A Zcash share is a bit bigger than from other coins, because it contains the equihash solution.
Some pools let you set a static difficulty. I would suggest you to take advantage of it and set it a bit higher so you save on bandwidth submitting shares, but your shares will be worth more in the end. It's all about finding a balance.