Yes. The Premium Programme and the Scaling Plan are two separate and independent programmes. FTMO Traders may participate in both programmes at the same time.
The Premium Programme is available to FTMO Traders who qualified through both the FTMO Challenge: 1-Step and the FTMO Challenge: 2-Step.
The only difference lies in how certain benefits are applied depending on the product. FTMO Traders who qualify through the FTMO Challenge: 1-Step start with a 90% simulated profit split from the beginning, so there is no increase of the reward split upon entering the Premium Programme.
Apart from product-specific limitations (such as the unavailability of rollover bonuses for the FTMO Challenge: 1-Step), the Premium Programme benefits are otherwise identical for FTMO Traders from both challenge types.