Firstly both floors need priming with a sbr primer secondly I personally would put down a matting with it being a new build as there is still movement and the property won't be fully settled as for the bathroom I wouldn't use ply I would use 10mm jacker boards put down with a flexible adhesive using washers and 20mm screws about 10-15 washers per board I strongly advise against ply as I've seen too many issues eccuring with ply even screwed down every 50mm hope this helps with your tiling

Need to prime screeded floor before tiling and prime chipboard floor and either cover with plastic ply and use flexible adhesive and grout or use special adhesive for chipboard floors from Topps tiles and use GTI admix in with the grout.

Good Evening, The concrete kitchen floor will be fairly straight forward, as in you can put your adhesive directly onto the concrete (As long as it is clean, dry and no dust), What adhesive are you using? You say timber floor in the bathroom, is this floor boards or caper board? To be honest either way you should fit a thin ply board first then a flexible adhesive to tile, as the wood will move, using a standard adhesive could cause the tiles to Pop off. also i would recommend a flexible grout as well. Hope all that make sense, Many thanks

Hi I don't know how much a knowledge you have about tiling, for bathroom all depends on what type of flooring has been used you may need to put ply wood on whole area and screw down make sure no movement at all and then seal all around and joins of ply, there is different type of sealing material to use make sure get the right one for that then get the super flex adhesive have to work out amount of depending area coverage after that use flexi grout
Kitchen concrete floor if it's a good leveled floor then use concrete floor adhesive also if you using porcelain tiles you need to get suitable adhesive for that before you start seal the surface to prevent of dust also if you have underfloor heating then make sure the adhesive has to be suitable for underfloor heating as well if you need more info you can contact me
Good luck with that

The concrete must be dry seal with acrylic sealer you can install direct to substrate
Regarding bathroom make sure the floor can take the extra weight as some of the modern tiles are very heavy , no too timber use Bal board or Hardi backer board seal timber floor allow to dry then adhere boards to timber base and screw down would recommend 6 inch centres seal the boards then you can tile to the boards once sealer is dry use Most s1 adhesive are good but for best results a s2 adhesive is far better
This will give you the best results and last for years as long as you solid bed method is used