How to operate across teams as a senior/medior dev who is not team leader?

Our company recently got acquihired by another company as we're a team specialized in GenAI in our logistics domain which is rare.

Someone who is a manager in another team approached me with interest to use my expertise with GenAI effectively which could save them 2 hours per task (50K tasks in like last 10 years)

I've talked with them 2 times now and they're interested in us collaborating , me or maybe also others. Our team wants to collaborate with others and add value.

How do I bring this to my current team? Especially the Head of Tech who is like my manager, he often doesn't want me to operate on my own. And am concerned that by sharing this collaboration opportunity he'll say something like he takes over from here or something.

The goal is to increase collaboration between teams and also would love to add value across teams, but not sure how that works with tasks on 1 team while also having tasks at another team.

I was thinking about sharing in the standup that I've met team x and they are interested in collaborating on y there will be a follow up , I'll keep you informed. And telling product owner that I would like them to be there in the conversation.

I feel like the moment I start going across teams I'm acting beyond my role, taking lead and stepping on others toes and not sure who to report to anymore.

Thanks in advance!