I was listening to a bradsmith pod cast on hops. It is a few years old. the guest worked out in hop growing region of Washington state. I forget if he was a university guy, and FDA guy or what, but he focused on growing hops.
Anyhow, Hops can give 4 flavors to a beer (and well any beverage) based on the variety and the temps. The flavor molecules are temperature sensitive, and can be driven out by heat.
The four flavors are grassy, citrus, piney and bitter. I remember grassy is very low in temp, and if you make a tea of the hops and have it above say 70 or 80 deg F it will drive off most of that grassy flavor. I don't remember if citrus or piney was next. I remember that bitter was last, and highest temp. So if you boil the hops for any amount of time, you will drive out the other three and leave yourself with just bitter. Obviously variety of hops matters, as some have more bitter, or more pine or more citrus. But the basics of driving out the flavor based on temp still applies.
Which getting to your question depends on what flavor you are after. Is it bitter? Then look for a bittering hops, and look to make a tea with it. I'd use about 1 to 2 cups per gallon - regardless of the amount of hops - which you probably also have as a per gallon. If it is one of the other flavors, make a tea but use say 150F water, not 212. Don't keep a boil. In fact for bittering, boiling may be a good idea and longer the boil the better. In beer making they recommend some - but not all - of the malt for getting better hop utilization. If you can use some of your honey in the boil. I personally don't boil my honey when making mead any more, so I'd sacrifice some of the honey for the boil, but not all. The honey aromas are also lower temp and come off because of that.
lastly I note that this is a sparkling mead - that is good. The reason beer drinkers have to drink it, rather than rinse their mouths like wine drinkers is so the bubbles in the beer can pop on swallowing bringing the aromas into the nasal passages where we can taste them. Oh yeah +1 or more for the hop sack no matter what you do.