I must thank you for extending warm greetings to me. The same goes to you.
Does "the same goes to you" mean I return the warm greetings to him? Thanks.
It is not a native phrase, to my ear. 'The same goes for you' is a similar phrase, but it is usually argumentative, not supportive. If you wish to extend sincere greetings, then you should not take short cuts.
Thank you for extending warm greetings to me, and I would like to offer you my best wishes as well.