Finnair has recently changed the access rules to the Premium Lounge at Helsinki Vantaa, located in the non-Schengen area of the airport. Previously any eligible passenger has been given access as long as the passenger has a OneWorld Sapphire or Emerald card and a same-day boarding pass with Finnair or a OneWorld carrier. Now they follow exactly what is written on the boarding pass regarding the lounge, and this means if you fly to a Schengen destination the boarding pass will indicate you should use the lounge in the Schengen area, and that is what they will also tell you at the lounge reception
The reason is apparently that too many Schengen passengers sneak over to the non-Schengen area as the food and drinks options in the Premium Lounge are vastly superior to the Schengen lounge and there are usually also fewer guests. It has also been possible to visit the lounge during a transfer from a non-Schengen flight to a Schengen flight. But as it looks now this will also no longer be possible
Access to the Finnair Premium Lounge will only be granted to passengers actually departing Helsinki on a non-Schengen flight the same day, either on a longhaul flight to Asia or North America or to a non-Schengen destination in Europe such as Russia or the United Kingdom. And of course you still need a Finnair Gold or Platinum card or a OneWorld Sapphire or Emerald card to access.