It really depends upon your employer's policies and expectations, and the most appropriate people to ask is your employer.
If you do a lot of candidate management including answering their questions, then you employer should let you use Linkedin as a point of contact. The drawback is when you change jobs, and all your contacts need to be reassigned.
That situation is mitigated if your recruiter group is a small group and you all use a single point of contact on Linkedin. Scale becomes problematic if you are say a Google recruiter and the candidate to recruiter ratio is off the charts. In which case, your employer may choose to let you use your individual Linkedin point of contact, with the understanding that they will have to manage the eventuality that you'll leave eventually.
As I said, it all depends upon the employer's candidate/recruitment ratio situation, the number of recruiters available to your employer, whether your employer actually has a policy and more likely in the case of most employers - that your employer has not thought at all about the subject and is choosing to let you handle the issue by yourself.
You won't know unless you ask your employer point blank.
As a side note, I once asked one of my employers a question that they had not thought about. The employer immediately reacted by "volunteering" me to lead the effort to come up with a policy for that issue. My staff and management did not let the fact that they liked me get in the way of treating me like an eager beaver :) Since the effort was successful, someone not involved in the effort took credit for the result and my part was made invisible in plain sight :)