I have a Cerbo GX, 2 Smartsolar mppt regulators, smartsolar inverter, Smartsolar BMV-712.
They are connected with VE-direct to the Cerbo GX.
Will it work without the VE-direct (using bluetooth instead) and is there any disadvantages in either way?
No, Victron devices cannot connect to the Cerbo via bluetooth.
Can Globallink connect to Victron devices via bluetooth?
Certain Victron devices can connect to the GlobalLink 520 via bluetooth, yes, but the GlobalLink cannot connect to the Cerbo. Since you already have the Cerbo, would recommend just wiring your devices to it as designed, but look at the Cerbo and GlobalLink user manuals if you’d like to learn more:
https://www.victronenergy.com/media/pg/Cerbo_GX/en/index-en.html
https://www.victronenergy.com/media/pg/GlobalLink_520/en/index-en.html