Hi, hope somebody can help with this. We use mahogany veneers on some of our custom furniture in the Philippines and have had good longevity with it for indoor use. Recently a customer ordered some living room pieces( chairs and coffee table) with the veneers on the flat surfaces but had told us that it has started to warp and delaminate in some parts of the applied surfaces. The only thing I could think of is because they are in a cooler climate which is up in Baguio, an elevated area of the Country which has year round cooler temps. I wanted to see if anyone in the US or colder countries have any advice on what to do when building furniture with mahogany veneers. Thanks for all help.

Cool temperature is not usually a factor in veneer or adhesive failure. More often it is the relative humidity that is the cause. It may be that the elevated location might be drier than your tropical coastal location.
You don't mention the substrate, the type of glue so I can't be specific.
For me the mahogany veneer I get is not true mahogany but an African wood like khaya. It is very stable as veneers go and I haven't had problems even though my temperatures vary from -30 to 30°C.
We get failure and warping because cold winter air is very dry.