Tier-2 general dependent visa

[seasonlly]

Hi,

I changed my job in June 2020 and submitted my new Tier 2 visa application in April via the new company's visa agent. So far I haven't got any update regarding my new visa application (no appointment booking email, no biometric reuse email).
My spouse needs to apply for the dependent visa from outside the UK so can't apply with me.
My current T2 visa with previous employer will expires in July 2021. I don't think I can get the desicion in the following weeks and I really want my spouse to come as soon as possible.
So I'm wondering if my spouse can apply based on my current T2 visa, or we still need to wait for the decision of the new application.
If it's possible to apply with my current visa, could anybody also let me know what employment-related documents should I provide? Like the contract from the previous employer or new employer?

Many thanks,
Wen