"On your 5 years RP, is it tied to your current employer in any way or have you needed your employer to sponsor it?"

I had a 2 year RP once upon a time. It wasn't tied to any employer! Trouble was, I had to surrender it at Beijing airport when I had to leave the country to deal with my father's death back in my homeland. Then I was back to square one. To qualify for said RP, I had to have a Chinese wife for at least 2 years and been in China for a continuous 2 year length of time at the time of application.

I'd have thought if you have a Z visa and an RP arranged by your employer, you needn't get a 5 year RP on spousal grounds.

While on the subject of visas and employment, it's maybe worth mentioning that some employers can get F visas for foreigners without at least a Bachelor's degree. Such visas can be got at the PSB offices of small cities in provinces where the Education Bureau based in the provincial capital won't approve letters of invitation for such foreigners, meaning no Z visa can be got. Small city PSB's can't issue Z visas, but can issue F visas, and some will do so knowing full well that the visa holders are teaching. They are likely in bed with the Chinese employers! It seems that the provincial capital PSB's have no authority there, so can't intervene to stop it and punish the Chinese employers and the foreigners illegally working for them. Another option to consider!