To conform to ST standard, all items (wires, switchgear, conduit, methods of installation and methods of wiring, even where the wires are buried/concealed, etc, etc, etc) must be SIRIM certified and following ST installation guidelines. This can't be determined from your information provided.

For example, your quote does not specify the brand of wire used, meaning it is impossible to know if this follows ST guidelines. (SIRIM publishes the list of manufacturers compliant to their certification)
Similarly, the size of wires (specified by the Cross Sectional Area of the conductor) being used for each circuit (lighting, power socket, water heater, etc) is not specified to determine ST compliance.

Ask them for a complete breakdown of what they are installing.
This is not enough information and quite vague.

If you look at the line item #8 "1hp - 2hp Air-cond point using 2x2.5 mm PVC cable" this is how the quote should be done so you know what wires are being used. (although 2 wires only? Not 3??)
Similarly, the 63A/4P ELCB should be listed with complete information, and so should the wiring for your water heater.

Look, if I were quoting for a job, I'd gladly list "Water heater point using 3x (L,N,E) 4 mm² MEGA cable with Schneider Vivace 20A dual pole switch (with neon indicator), c/w dedicated Maxguard 20A, 10mA protection RCBO in DB".

You're paying for it.... ask for full information, and in writing. Good luck.

You seem to be going to great lengths to defend your contractor. Maybe you don't realise that the quote forms the basis of the contract between you and your contractor. Maybe there is some other reason....Either way it's all cool with me as I'm not physically affected.

I just hope there isn't another thread in the future about what action to take when your contractor didn't fulfill something not quoted.

PS: I'm an "uncle electrician" but I keep up to date with all rules, am qualified, have certificates, fully computer literate, and try to provide everything to the last detail, even providing 3D drawings if necessary. That's a lousy excuse to use.