Tafunge25 No, the GA is valid to Domodossola both via Brig and via Locarno. You can see the entire range where it is valid on this map: https://maps.trafimage.ch/ch.sbb.geltungsbereiche?baselayers=ch.sbb.geltungsbereiche.mvp.data&layers=ch.sbb.geltungsbereiche.mvp-ga_s25&lang=de&x=925472&y=5920000&z=9. Note that there are construction works being carried out this summer on the line between Brig and Domodossola, so check the schedule shortly before travelling. The GA is of course also valid on the rail replacement bus services until Domodossola.