I add techs here in order I find or hear about them. If you know more - write a comment about that, I'll add them here.
Sometime later I'll rearrange this in the same order as they are written in the game.
REMEMBER: Unique Techs (like every passive tech) take effect only on NEW building. So if, for exmple, you want to train Axe Warriors, you have to deconstruct your Barracks and build Axe Barracks instead.

• 1. Clay Pit + Sharpened Axes/Log Tents/Sturdy Shovels = Petrified Wood Clay Pit (Endlessly produce Clay and occasionally Logs)
  
• 2. Reed Field + Stone Mine/Adobe Oven = Raised Reed Field (Reed Field that can be anywhere but material is Bricks instead of Clay)
  
• 3. Clay Pit + Stone Mine/Adobe Oven = Efficient Clay Pit (produces 2 Clay instead of 1)
  
• 4. Archery Range/Bowyer + Braided rope = Longbow Archery/Longbow Bowyer (Trains Longbow (Archers with increased range but also increased time between shots))
  
• 5. Warding Apiary + Stone Mine/Adobe Oven = Towering Bee-boxes (A defensive ward that scares and distracts attackers and fertilizes nearby crops)
  
• 6. Paddy + Stone Mine/Adobe Oven = Raised Paddy (same as Raised Reed Field - can be placed anywhere)
  
• 7. Barracks/Swordsmith + Stone Mine/Adobe Oven = Shield Barracks/Shieldsmith (trains Shield Bearers)
  
• 8. Barracks/Swordsmith + Sharpened Axes/Log Tents = Axe Barracks/Axesmith (trains Axe Warriors)
  
• 9. Ceramics Production (attachment to house) + Stone Mine/Adobe Oven = Ceramics Carver (uses Bricks instead of Clay)
  
• 10. Elevator + Windmill = Windmill Elevator (Elevator powered by wind)
  
• 11. Canal + Well = Irrigation (same as Canal, but on any level near a Well)
  
• 12. Cliff Awning + almost any round house = Umbrella (placed on top of a house, gives Rainproof)
  
• 13. Grenades + Snail Bridles/Glassblower Dome/Ceramics Production = Acid Bombs (bombs that do high damage to units but low damage to buildings)
  
• 14. Beast Incense Emitter + Incense = Speedy Beast Incense Emitter (same as Beast Incense Emitter, but also gives speed buff)
  
• 15. Overhang + Frilled House = Frilled Overhang (A rounded overhang, that automatically connects to nearby access points)
  
• 16. Weaving Hermit + Foraging Hut = Hermitage (Hermits no longer have to wait for their product to be taken before producing again)
  
• 17. Canal + Clay Pit = Muddy Canal (same as canal, but also spawns piles of clay)
  
• 18. Elevator + Blastpowder Distillery/Boiler = Furnace Elevator (Elevator, that do not requires a brave to work)
  
• 19. Backery + Adobe Oven/Stone Mine = Brick Pie Oven (costs Bricks instead of Clay and produces 2 food instead of 1)
  
• 20. Mud Arches + Adobe Oven/Stone Mine = Stone Arches (A large stone bridge that can also be built on)
  
• 21. Colporteur + Canvas Press = Focused Press (The Calporteur travels across the lands to the karma in search of a specific desired resource)
  
• 22. Fishing Tower + Canvas Press//Silk Loom = Covered Fishing Tower (A fishing tower that is cowered by an awning so it can work during the rain)
  
• 23. Crop Row + Blastpowder Distillery/Boiler = Fertilized Crops (grows extremely fast, but construction material is changed to Blastpowder)
  
• 24. Bridge + Lumberjack = Plank Bridge (well, it is Bridge that is build with Planks instead of Bamboo. Dunno why they made it a Unique Tech, since Lumberjack changes all Bamboo requirements to Planks)
  
• 25. Spear Laager/Spearsmith + Defensive Spikes = Halberds
  
• 26. Mighty Pie + Fishing Tower/Fishing Net/Haken House/Fishmonger = Fish Pie (instead of 4 Reed uses 2 Fish)
  
• 27. Drawbridge + Blastpowder Distillery/Boiler = Furnace Drawbridge (Drawbridge, that do not requires a brave to work)
  
• 28. Climbing Pole + Lumberjack = Stairs (same, but from Planks)
  
• 29. Lumberjack + Rune Axes = Plank Axes (Damaging a tree yields a wood plank)
  
• 30. Fishing Tower + Lumberjack = Fishing Dock (A long dock built over the water for fishing, closer to the water)
  
• 31. Temple/Library + Beast Incense Emitter/Incense = Censer (Priest that instantly converts 1 guy and heals)
  
• 32. Foraging Hut + Canvas Press = Specific Foraging Hut (A hermit's hut that scavenges for food and one chosen resource)