Ahh if you have the recover phrase - yes you have the private keys and will be able to access them
Good think they have changed it (I used them in the beginning and do not remember how it was back then 4 years ago..)
But as they give you the keys it is you how has access to the wallets and you will be able to access them the same way you did with BCH
Well... when I claimed BCH I did it two ways.
At the time of the BCH fork my BTC was in 'imported addresses' which were BTC addresses imported into the new blockchain wallet interface from the previous incarnation of the blockchain wallet. These imported addresses were not held in the user's main blockchain wallet, and they were not recoverable using the recovery phrase for the main wallet. Rather the user was given the exact private key for each imported address. Therefore it was possible to use the private key to claim your BCH from each address. In my case I used a process with Coinomi where I entered the private key for each imported address and was able to claim my BCH that way. I used that process to claim approximately half of my BCH.
Then blockchain announced they would support BCH and would provide a tool for claiming BCH. So I decided to wait for that to go live to claim the rest of my BCH rather than use Coinomi coz tbh that process was a pain in the neck, Coinomi's BCH support was quite buggy. So I was able to use the blockchain.info tool to claim the second portion of my BCH from the last of my imported addresses.
However at the time of the BCH fork I didn't have any BTC in my main blockchain wallet it was all in imported addresses, so I havent ever tried to claim BCH using the recovery phrase. Im not sure how that process works and which wallets etc would have been used at the time in that process.
I have since moved my BTC from the imported addresses into my main blockchain wallet address, so in my case the process for claiming BCG is going to be different to how I claimed BCH: I'll have to use the recovery phrase rather than the exact private key associated with each imported address.
I assume the process will be as I posted above. Using a wallet other than blockchain, that supports BTG and supports importing addresses via a recovery phrase.
As far as I know blockchain.info wont be supporting BTG straight away, and if they do provide support its likely to be weeks / months after the fork, like for BCH.
But yeah, I think we can use the recovery phrase to claim BTG with another wallet. Hope Im right about that.