Turns out the problem wasn’t in the driver or the cluster. I had one crucial element missing from my connection string. I had to use the ServiceName parameter instead of the SID parameter since the Listener was setup that way.

Final connect string:
jdbc:macromedia:oracle://10.33.50.55:1521; ServiceName=PODQASVC; AlternateServers=(10.33.50.56:1521); ConnectionRetryCount=180; ConnectionRetryDelay=5; sendStringParametersAsUnicode=false; MaxPooledStatements=300

I got this from a link Steve Erat posted on his site, but I’ll post it again here for redundancy’s sake.

Connection Failover with the Oracle Driver