WiFi Media Streaming - DD-WRT Client Bridge

I have 2 Netgear routers that run dd-wrt and are connected via wireless client bridge mode. The AC1900 resides in the office and is the main router. The AC1450 is in the living room and has a Seagate Central 2TB plugged directly into it.

I stream movies from the seagate to a raspberry pi that is also connected directly to the living room router.

Is the client bridge mode smart enough to know that the seagate and the Pi are directly wired? Or is the signal sent from the seagate to the office router and back to the living room router? Should I connect the seagate to the main router instead?

Currently, a movie will buffer every now and then causing me to think I should move the seagate but I'm not sure if that is the right move technically.

Thanks for any help.