What does my career look like in a MM AM in a Multi-Asset team?

A few thoughts for you: 

- The experience you get will be very marketable. In most cases you are right, portfolio manager is a very viable long term goal should you choose that. That could take a variety of forms, of course. You'll also get broad experience in portfolio construction, overlaying 'big picture' research on top of various allocations and specifically how to build a portfolio. All of these are very good things to have experience with, not just how to build portfolios but how to actually implement the ideas you come up with.. that's often key. Some of it will obviously depend on what you are working on and the firm you are at - but there's some pretty cool offshoots and model portfolios of all types, different strategies using all sorts of different cross asset class analyses... etc. 

- Your opportunities will also range widely - you could theoretically go run a multi asset fund (quite literally) like, say, a black rock fund. You could also go the more tailored, institutional route where you work with clients like, say, an endowment to build and execute a portfolio - consulting/OCIO work effectively. Those are just a few examples, there's a ton of opportunities in either route. Those are more on the 'portfolio manager' or 'client portfolio manager' type route. Theoretically - you could parlay it as well into wealth management building different types of portfolios.. list goes on. 

-  Asset owners are also an option, you could conceivably be a CIO for a mid (or even larger!) sized institution, using those skills to manage their portfolios. You could also end up within a specific asset class, choosing to specialize as well. I think, largely, this is an underrated and often not thought of path until you are in the industry a bit...some of this is that managing in house has picked up, not just for the big guys and a proliferation of jobs outside of traditional big 'asset managers' 

I always hate to give a 'typical' path within Asset Management as it's so broad, but I think the above are fair - there are probably many others, some may be very obvious that I'm missing... but hopefully somewhat helpful.