1996 Honda Civic Radiator cap

Engine Cooling problem
1996 Honda Civic Front Wheel Drive Automatic

My cooling system is giving me problems. The temperature needle goes up to about 3/4 when stopped in traffic or goin through a drive through. I have changed the water pump, thermostat and radiator. However the needle still goes up when in traffic. The mechanic have tried almost everything, only thing left is the radiator cap and getting the radiator flushed. However I want to change the radiator cap to start with. The one on the radiator now has a 1.1 bar pressure rating. The one i have to put on has a 1.35 bar pressure rating. I was wondering if that could work or would it cause problems in the short and long run. It is a spoon type D cap. I read that it increases the boiling point or something but how good and safe is that for my ride. It has in the B16a5 engine. Link for radiator cap description.

http://www.funkypower.co.uk/catalogue.php?make=HONDA&model=CIVIC&year=1996-00+CIVIC&level1=ENGINE+BAY+DRESS-UP&level2=RADIATOR+CAPS+%26+CAP+COVERS&level3=&id_product=2960