I have submitted stage 1 and stage 2 but have not seen any form that asks for IELTS or similar. I am curious if this is even a requirement as I don’t find it on official guidelines. However, different websites have mentioned about knowing functional English or 4-5 IELTS score.
No need of IELTS for yourself, but your spouse need to prove english level through a very basic exam.
For entry clearance and extension, English language requirement is not applicable. For settlement it is mandatory for all.
For Settlement, what level of english need to prove like in the form of bands in IELTS?
It seems that there’re easier options than IELTS UKVI (where, according to gov.uk, one must score at least 4 points in every part), for example - IELTS Life Skills B1 test (which is either pass or not). I’d suggest watching youtube videos regarding those tests to understand which one to choose and checking gov.uk in case anything changes.
Is there any requirement of english language for spouse to get UK Global talent visa (dependent) under main visa holder?
There was no such requirement for dependants of Global Talent visa main applicant, as far as I know.
This is not legal advice and I’d suggest checking with gov.uk as rules can change at any time.