I don't know about the compatibility with 64 bit os's for some of the agent components. The reason they're not installing is definitely due to the query the collection uses:
(see the last part of it which specifies win32)
SELECT distinct r.Guid
FROM vComputer r
WHERE r.Guid IN
-- Resources with AM Agent older then the current build, but also with a new 6.0 version of the Altiris Agent installed
(SELECT CA1.[_ResourceGuid] FROM Inv_AeX_AC_Client_Agent CA1
WHERE (CA1.[Agent Name] = 'Application Metering' AND (CA1.[Product Version] != '6.1.31' OR CA1.[Build Number] != '31'))
OR (CA1.[Agent Name] = 'Altiris Agent')
GROUP BY CA1.[_ResourceGuid]
HAVING COUNT(DISTINCT CA1.[Agent Name]) > 1)
OR
r.Guid IN
-- Resources without AM Agent installed, with 6.0 Altiris Agent and not a Server machine
(SELECT distinct [_ResourceGuid] FROM Inv_AeX_AC_Client_Agent where [_ResourceGuid] not in
(SELECT CA2.[_ResourceGuid] FROM Inv_AeX_AC_Client_Agent CA2 WHERE CA2.[Agent Name] = 'Application Metering')
AND [Agent Name] = 'Altiris Agent'
AND isnull(r.[OS Name],'Professional') not like '%Edition%'
AND isnull(r.[OS Name],'Professional') not like '%Server%')
AND r.IsManaged=1
AND LOWER(r.[System Type]) like lower('%win32%')