Many abilities like this usually say you can't get the same ability as one you already have. This one does not.
As written, you have two different Life Links, and may keep party members under both simultaneously.
However, run it with your GM first, as I expect resistance.
It does not matter much, if you can have more than one lifelink, as the damage does not vanish.
I have sometimes wished I could transfer more with my lifelink, but sometimes that would have been fatal. When the group comes under AE attacks and you lose 20 hp each round in addition to the 70 you just took yourself it is close enough. Losing 40 would have forced me to abandon the links or die myself, so I wouldn't have had them anyway.
I usually rely on Shield Other to preserve our main tank (from crits) and lifelink to regenerate everyone else a little.
So, if your DM is OK with it, be prepared that it might occasionally be impractical, unless you have crazy CON.
I once ran a spirit guide with double life, but the healing was already such overkill, I started moving my spirit to flame so I could deal some damage when the healing wasn't needed.
All you really need to be a decent healer is channel with a high charisma and the shield other spell on your most damage-prone team members.
If I were to take a spirit guide Oracle with the life mystery and then take the life spirit, selecting life link for both, would I get double the number of links?
If it did double up, could I place one of each links on the same creature to double the link healing?
So the goal is to see how fast your oracle can die?
Also seems like your PC would either be masochistic, or suicidal selfless, to even consider either ability in use on a regular basis. And if they consider it a reasonable option, be very wary of NPCs which charm or dominate your PC, as commands like "protect me" will mean establishing a life link (or two)...
I will note that the life link is one of the few life oracle abilities that can heal undead.