There's a few components to handle to beat Bunny Hunt.
1) Unit counters. Some of the bunnies are vulnerable to armor-piercing weapons (tank shells, rocket infantry and advanced guard tower missiles), others to machine guns or high explosive weapons (rocket launchers).
Try to build a diverse arsenal of both tanks and rocket launchers, and for defense, use both Advanced Guard Towers and regular Guard Towers. Early in the game, when you haven't teched up yet, a good mix involves Hum-vees, Medium tanks, and Guard Towers as well as Rocket Infantry.
After teching up, Mammoth tanks and the X-O Powersuit are good because they are both "generalist" units that are effective against all armor types and as such, all of the different kinds of bunnies. A powerful, easy-to-micro late-game mix usually includes the X-O, Mammoth tanks, and possibly some Rocket Launchers if you feel you benefit from their long range.
Micromanagement of course helps, particularly formation of keeping the tanks / X-O in the front and Rocket Launchers in the back.
2) Economy. Aggressively build refineries, sell extra ones off if you lose harvesters. Seek new fields to harvest, clear them of bunnies and expand there by base-crawling or building a spare MCV, then build refineries there as well. Build a repair facility and repair damaged vehicles.
3) Scouting. As you said, this is hard to do with individual units because they get destroyed. So you need to perform "recoinnaissance by force": gather an army and attack with it to a direction. Pay attention to where the bunnies are coming from, that way you'll also discover the bunny holes.
Veteran units in DTA have high sight range and so can also be used to effectively scout. A veteran Hum-vee or Medium tank is good for this.
If you've already survived for 1½ hours, it sounds like you shouldn't be very far from beating it. Usually people say that the beginning is the hardest part of the mission.
Rampastring
Rampastring joined
Commander of Nod's northern forces, programmer, reverse-engineer, game designer and a 東方 lunatic who enjoys swimming in the cherry blossom -colored sea. Original creator of the CnCNet client that is used by almost every active Tiberian Sun and Red Alert 2 mod. Co-leader of @[Dawn of the Tiberium Age](mods:the-dawn-of-the-tiberium-age:10865) and the author of various Tiberian Sun game engine improvements. Ex-staff of @[Twisted Insurrection](mods:twisted-insurrection:10974). Enjoys all cute things and large groups of enemy units to wipe out.