If you have a base action power of three and the gain additional industry value, can you then get the 5-power bonus (assuming your industry level is 5 or beyond now) and can you construct a building?
Thanks for any help in advance
You already got the answer, but I'll clarify a bit because it may help with other questions...
The 5-power reward is for doing a 5-power action, period. You only get power from your president, assistants, buildings, and maybe the station token. You cannot buy more power.
You don't spend power on tech cards, you spend Industry points. You get some Industry points based on your power, and you're allowed to buy more industry points to afford a higher cost tech.
Buying industry points has nothing to do with the 5-power bonus though. It also has nothing to do with whether you can build or not.