After reading you comments, I see one flaw: if you are logging into the e-mail with your password and using the OTP authenticator on the same phone, and that phone was compromised, then the advantage of the OTP authenticator is redundant.
But to answer your original question: it seems recovery options do not increase security unless you got hacked.
And if you were actually hacked and you want to plan for that, if the other answer about recovery questions being delayed after a password change is true (which seems plausible but you must test first) then I'd bet that a recovery phone number would be a better bet than a recovery e-mail. I'd bet this simply because the avenues for hijacking a phone number would be very different to the avenues for hijacking an e-mail, which basically just means more work, and more time, and security is mostly a question of time. Again, you'd want this phone number on a separate phone, but you'd have to check this number frequently to ensure it was still active, and hadn't been cancelled and reposted by your carrier - or even moved to an account on a different carrier - at a hacker's request.
So in conclusion - adding a mobile number introduces a new point of failure for you getting hacked, but, simultaneously, may reduce the damage done if you are hacked. Seems quite a double edged sword !