Entangled but not tethered + flying = normal entangled.ou move at half speed, you cannot run or charge, and you take a –2 penalty to your AC, attack rolls, Reflex saving throws, initiative checks, and Dexterity-based skill and ability checks.
Entangled +tethered or grappled= RAW you can't move, so you'll have to hover or drop like a rock.
If you're grappling say, a pteranadon, I wouldn't be surprised if the DM says it can just take off with you. All movement being relative and all that...