The ATES 1.2 templates are the same as the BTES 1.0 templates but use the ATES 1.2 BC instead of the BTES 1.0 BC. More information on these templates can be found in BTES 1.0 templates and more information on the ATES 1.2 BC can be found in ATES 1.2.
Overall an ATES system is an open system and uses the groundwater itself to store the thermal energy, while a BTES system is a closed system and uses pipes in the underground as a heat exchanger to transfer thermal energy. The control outputs are a bit different for the ATES BC compared to the BTES BC because it has more valves to control.
Also, one of the optional controls in the BTES templates where the heat pump can directly deliver cooling and heating to the building when there is simultaneous heating and cooling demand, is standard in the default templates of the ATES 1.2 templates.