you can retrieve account object via following xml in metadata api
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
<types>
<members>Account</members>
<name>CustomObject</name>
</types>
<version>53.0</version>
</Package>
once you retrieve the data related to it you can find the account.object xml file which is already in your bitbucket repository as you have said
under account.object xml file you will see the record type tag with following sample data
<recordTypes>
<fullName>Customer</fullName>
<active>true</active>
<label>Customer</label>
<picklistValues>
<picklist>AccountSource</picklist>
<values>
<fullName>Other</fullName>
<default>false</default>
</values>
<values>
<fullName>Partner Referral</fullName>
<default>false</default>
</values>
<values>
<fullName>Phone Inquiry</fullName>
<default>false</default>
</values>
<values>
<fullName>Purchased List</fullName>
<default>false</default>
</values>
<values>
<fullName>Web</fullName>
<default>false</default>
</values>
</picklistValues>
</recordTypes>
For example if for accountscore picklist field if i want to add/remove some value for customer record type oly then i will do that here
Also just make sure your picklist is added under field metadata tag on account object as well like this
<fields>
<fullName>AccountSource</fullName>
<picklist>
<picklistValues>
<fullName>Web</fullName>
<default>false</default>
</picklistValues>
<picklistValues>
<fullName>Phone Inquiry</fullName>
<default>false</default>
</picklistValues>
<picklistValues>
<fullName>Partner Referral</fullName>
<default>false</default>
</picklistValues>
<picklistValues>
<fullName>Purchased List</fullName>
<default>false</default>
</picklistValues>
<picklistValues>
<fullName>Other</fullName>
<default>false</default>
</picklistValues>
<sorted>false</sorted>
</picklist>
<trackFeedHistory>false</trackFeedHistory>
<trackHistory>false</trackHistory>
<type>Picklist</type>
</fields>