No. Getting your multi-engine rating in a Seminole would require you to have a complex endorsement before you take your checkride.
Right -- either the endorsement, or PIC time in a complex airplane before August 4, 1997.
The grandfathering comes in to having logged PIC time in a high performance aircraft before a certain date.
Since a Seminole is not high performance under the current rules, you don't need to meet the HP requirements to be PIC in one, and you would not be grandfathered for HP for PIC time in one.
BTW, there is a "gotcha" involved in the HP/complex area. Before 8/4/97, there was a requirement for additional training and an endorsement to act as PIC of a "high performance" airplane, with that term being defined as
either retractable/controllable prop/flaps
or over 200HP -- one endorsement earned in either, good for both, so if you got it in an Arrow, it was good for a 182, and vice versa. Only problem is that when the FAA split them in 1997, they kept the HP name for over 200HP. As a result, a pre-97 "high performance" endorsement earned in an Arrow (which is under the current rule complex but not HP) does not give you PIC privileges in an over 200HP airplane today, but the PIC time you got in doing it gives you complex PIC privileges today.
As an example of where this can be an issue, I tripped over a guy who'd earned a "high performance" endorsement in an Arrow in the early 90's, but never flew an over-200HP airplane until he bought a Lance in 2003. The instructor who checked him out in it either didn't notice or didn't understand the limits of that old endorsement, and did not add a post-97 high performance endorsement to his logbook. He happily but illegally flew it for several years until he came to me for his instrument rating, at which point my review of his logbook unearthed the problem. I added the correct endorsement after the first day's flying with him, but he's lucky nothing bad happened during the intervening years.
For tailwheels its 1970 something. 71 or 76? I cant remember.
Complex: August 4, 1997
High perfomance (current definition): August 4, 1997
Tailwheel: April 15, 1991
High altitude aka "pressurized": April 15, 1991