New member.. first question... go easy on me

I recently took a new consulting job which will have me traveling to the same location each week for the next 2 yrs and staying for 3-4 nights/week. I'm currently looking to get another rewards card to compliment the Delta Gold Amex that I already have. My client prefers that we stay at a Wyndham as our first choice, or a Marriott as a second choice.

I've heard mixed reviews on both Wyndham and Marriott's reward programs, so my newbie question is... I see that the SPG Amex is often recommended, but is it worth getting the SPG amex to accumulate points with Starwood even though I will be staying in a Wyndham/Marriott, or would you advise that I get a different credit card for the hotel I will be staying at most and try to rack up as much points with that hotel? Or... maybe even a more universal card like the Chase Sapphire.

I intend on using my points for domestic travel to fun locations, such popular vacation destinations, Vegas, and major cities like Chicago, NYC, and San Francisco.