I can control everything in my Alexa eco system, With my car infotainment system... even when not in the same zip code... I Don't think it matters which device is on what Ghz, or wifi router, as long as the router/access point is permitted access. On the other hand, if you have some Hue bulbs set up as Blue tooth devices, it may not control them the same due to the non/wifi connection. That's a user choice generally. If it requires a bridge for full features, I can almost guarantee it will require the bridge for full access by other devices.
Keep in mind though, I have a 2023 Honda Accord, with Alexa built in. I had to give the car access to my Alexa account, and my Google account for maps and Alexa connectivity. This stuff with me in the car... not sure if my phone has to be with me or not, except for Apple Car Play functions.