The positive crankcase ventilation system is sucking the filtered air through the breather in the valve cover. The air then mixes with the crankcase gases and is scavenged through the PCV valve by the intake vacuum.
In other words, connecting both breathers to the same catch tank just negates the whole system. Fit a small filter on the valve cover. Like this:
http://www.ebay.co.uk/itm/NEW-Breath...item45f79c00e3
Keep the PCV valve connected to the intake.