Does Tiger have one install CD for both architectures?
According to Wikipedia, only Tiger Server included a universal DVD: (http://en.wikipedia.org/wiki/OS_X#Version_10.4:_.22Tiger.22):


  Mac OS X v10.4 "Tiger" was released on April 29, 2005. (...) On January 10, 2006, Apple released the first Intel-based Macs along with the 10.4.4 update to Tiger. (...) Only PowerPC Macs can be booted from retail copies of the Tiger client DVD, but there is a Universal DVD of Tiger Server 10.4.7 (8K1079) that can boot both PowerPC and Intel Macs.


I happen to have a retail Mac OS X Tiger DVD (part# 2Z691-5305-A) and my MacBook Pro didn't boot from it, which seems to confirm the information above.

That said, Apple may have released other Tiger DVDs. The short URL provided by the OP's in the comment below points to an auction of a purported free upgrade for Intel-based iMac owners with P/N 1001123:



I found here a very similar, if not the same, product:



I'm pretty sure this DVD won't boot from a PowerPC computer, nor will include drivers for any hardware other than the Intel-based iMacs it was intended for. Also notice that the auction is an upgrade, that means, you need Panther installed on your Mac.