The Adelaide trio feature in both the T20 and one-day squads, with McGrath named captain of both sides.
The 24-year-old allrounder captained Australia A earlier this year during a tour of the UK, while she has also taken the reins of the National Performance squad in the past.
“Tahlia has chipped in with some important performances and is an exciting emerging leader,” National Selector Shawn Flegler said.
“She showed great leadership attributes throughout her time in the National Performance Squad and on past tours so this will be another opportunity for her to further develop those skills.”
McGrath has struck a high score of 65 not out so far in rebel WBBL|05 and she’s also collected eight wickets at 23.12.
Patterson is in currently in career-best form in both formats of the game but has not featured in an Australia A side since 2016.
Averaging 29.75 in rebel WBBL|05 from 10 innings, the talented 25-year-old has been striking at 124.6 this campaign and is also a dynamo in the field.
“Bridget has been a really important player for the Strikers this season and has provided great support in the middle order,” National Selector Shawn Flegler said.
“Bridget has been in previous (national) squads and has gone away and done well in domestic cricket, which is great to see and we’re really happy to see her force her way back.”
Wellington is continuing to push her case for national selection after not having her Cricket Australia contract renewed for the 2019-20 season.
An exciting leg-spinner and handy middle to lower order batter, the 21-year-old has taken 10 wickets this WBBL season at an average of 21.4.
The Australia A side begin their campaign just days after the WBBL final on 12 December in Brisbane.
Australia A v India A fixture
12 December: 1st 50-over match, Australia A v India A, Allan Border Field, Brisbane
14 December: 2nd 50-over match, Australia A v India A, Allan Border Field, Brisbane
16 December: 3rd 50-over match, Australia A v India A, Allan Border Field, Brisbane
19 December: 1st T20, Australia A v India A, Bill Pippen Oval, Gold Coast
21 December: 2nd T20, Australia A v India A, Bill Pippen Oval, Gold Coast
23 December: 3rd T20, Australia A v India A, Bill Pippen Oval, Gold Coast
Australia A ODI Squad
Maitlan Brown, ACT
Heather Graham, WA
Phoebe Litchfield, NSW
Tahlia McGrath (c), SA
Bridget Patterson, SA
Georgia Redmayne, QLD
Sammy Jo Johnson, QLD
Molly Strano, VIC
Annabel Sutherland, VIC
Rachel Trenaman, NSW
Belinda Vakarewa, TAS
Amanda-Jade Wellington, SA
Tahlia Wilson, NSW
Australia A T20 Squad
Maitlan Brown, ACT/Melbourne Renegades
Erin Burns, NSW/Sydney Sixers
Josie Dooley, QLD/Melbourne Renegades
Heather Graham, WA/Perth Scorchers
Phoebe Litchfield, NSW/Sydney Thunder
Tahlia McGrath (c), SA/Adelaide Strikers
Bridget Patterson, SA/Adelaide Strikers
Sammy Jo Johnson, QLD/Brisbane Heat
Molly Strano, VIC/Melbourne Renegades
Annabel Sutherland, VIC/Melbourne Stars
Belinda Vakarewa, TAS/Hobart Hurricanes
Elyse Villani, VIC/Melbourne Stars
Amanda-Jade Wellington, SA/Adelaide Strikers