I recently hooked up a hot tub that required a 240v with no neutral. (50A) I took a two pole 60 from the main service and ran 6/3 teck cable to a 2cct outdoor enclosure outside to within 5' of the tub. Into the enclosure I hooked up the red to the main the black to the other main and the blue to the neutral bus. I then put in a 2 pole 50A G.F.I breaker hooking the tail from the breaker to the neutral bus in the enclosure. From the tub ran a 6/3 tek cable to the enclosure hooking up the red and black to the breaker but not needing blue (neutral),because there was no neutral connecton in the tub. Is this still effective method of protection?

The gfi tail should be connected to the enclosure case not the neutral bus.
However, you didn't mention the bare. For the teck that runs between the main and the outdoor enclosure, the bare in the teck should be connected at the main panel ground bus and terminated at the outdoor enclosure case.
For the teck that runs between the outdoor encloure gfi and the tub, the bare in the teck should be connected at the enclosure case and terminated at the tub heater or pump case. The gfi monitors and trips on ground current flowing in the bare conductor. Without connecting the bare, the gfi won't trip and you will have a faulty installation.
Ensure all connections to enclosure cases are metal-to-metal solid connections.