I should of course just have consulted the T&C, where it says:

Lounge access is available to Gold and Silver Members travelling in any cabin on Emirates flights.

while http://www.skywards.com/Member_Benefits.aspx?SkinID=2 says :

Access to all Emirates and affiliated Business Class lounges

Knowing that other airlines let their elites enter lounges without flying own airline/alliance (LH SEN, e.g.), I think it was a fair question.

But thanks for the clarification.