Hello Flyertalk(ers). Is that a thing?

I have searched the forums and found similar discussions but was hoping for specific advice. I'm taking a last minute trip to Germany in the next couple weeks and found some (decent) deals. I think I'm going to fly on a combination of Air France and KLM airlines. Here is the dilemma.

I have somewhere around 20,000 miles on Alaska Airlines and anticipate getting a lot more this year for a few trips back and forth from work (the company pays) which will most likely give me "elite" status. My question is this:

Should I do the parter miles thing and earn more Alaska points on those flights or should I pick one of those and sign up for their loyalty program.

A couple factors:

- I live in LA if that makes a difference for the miles program.

- I do plan on making Europe trips about once a year for the next couple years (but will take whichever airline is cheaper).

- I will go back and forth to Alaska a lot this year and always on Alaska (the company will pay for it) but its unlikely I will ever go back after this job is over. Are these miles on Alaska "worth" stock piling. They seem to have the worst first class on all planes and would like to be able to eventually do business or super economy to Europe (based on my judgement of walking by on my way to the back).

Thoughts/advice?

Thanks in advance.