Chip antenna and PCB StackUp
You can certainly have your RF trace on the top layer, and the reference ground plane on layer 2 (or internal_1 as you call it) of a 4 layer board.  You would just need to ensure the transmission line width is sized appropriately for the height between the two layers and the substrate material.  You don't have to do anything special on the other two layers.  You can freely use layer 3 and 4 for planes or signal routing.