English Language Test for Spouse

[m.asif]

Hi All

I have applied for ILR in June based on 10 years. I am planning to apply ILR spouse visa (FLRM) for my wife once I'll receive mine. My question is if my wife pass english language test which is valid for two years can we use same test certificate in future? (for extension after 2.5 years and for ILR).
Secondly Would a B1 test certificate be acceptable for spouse visa as she don't want to do A1 test now and then B1 when she apply for ILR.

Thank you in advance.
M.Asif