Generally you would say something like
This presentation is copyrighted.
This presentation is subject to copyright
And you might also say
Would recording this presentation be considered copyright infringement?
Would recording this presentation infringe your copyright?
As for the example questions you posted, the first one sounds odd to me but I'd say it's probably acceptable and the listener will understand, but I'd say this instead:
I am attending a training session conducted by a third party training company. I want to audio record the sessions. Would this be considered copyright infringment?
For your second example there is a bit of ambiguity about your
this pronoun in the second sentence.
Say I am attending a meeting in my company, what if I want to record those meetings in my mobile phone for later writing notes. Is this subject to infringment of copyright?
I understand the meaning but what the question is really asking (at face value) is "Will my recording have its copyright infrigned?" which probably isn't what you want; the copyright you are concerned about is the meeting's copyright. So I'd say
Say I am attending a meeting in my company. What if I want to record those meetings in my mobile phone for later writing notes? Would this infringe the company's copyright?