Hi yannayoga,
If you mean whether individual latex layers are glued then Talalay latex will usually have glue seams in the larger sizes but you won’t feel them (see post #2 here). These are generally done by the manufacturer of the latex or a fabricator rather than the mattress manufacturer.
If you mean whether they glue the layers together then no because this would defeat some of the benefits of a component mattress with a zip cover because you wouldn’t be able to replace or exchange individual layers (see post #2 here).
If you mean whether they glue each side of a “side by side” split construction together or whether you would feel the split then as long as the cover and/or design is suitable for a split construction then no you wouldn’t feel the split itself although you would feel any differences in firmness on each side of the mattress (see post #2 here).
Phoenix